Sample Business Contracts


DC-2000 Pennsylvania Avenue NW Lease - The George Washington University and The Corporate Advisory Board Co.

Lease Forms

  • Start a state-specific lease for the rental of commercial property. Specify the term and rent due, as well as whether the landlord or tenant is responsible for property taxes, insurance, and maintenance and repairs.
  • When a tenant vacates commercial property before the lease term has expired, it may be able to rent the premises to a third party. The tenant would be the sublessor and the third party would be the sublessee. Besides preparing a sublease, both parties will want to review the provisions for assignment or subletting in the original lease agreement between the landlord and the sublessor.
  • Tenants of residential property should prepare a sublease agreement if they are seeking to sublease a room or the entire apartment or house to a third party. All parties should review the original lease agreement to see if there are any restrictions on subletting or assigning the premises.
  • Triple net leases are a type of commercial leases where the tenant has to pay for property taxes, insurance, utilities, and maintenance, in addition to the monthly rent.
  • When renting an office space, tenants should understand the amount of the rent and duration of the lease. Other important terms include whether the space can be subleased, which parties are responsible for maintenance, and whether any furniture and furnishings will be provided.


                              AGREEMENT OF LEASE
                                   (OFFICE)
                                      FOR




                     THE CORPORATE ADVISORY BOARD COMPANY



                                 SUITES _____
                        2000 PENNSYLVANIA AVENUE, N.W.
                            WASHINGTON, D.C. 20006





The Corporate Advisory Board Company Lease
June 23, 1998 Final
<PAGE>

                               TABLE OF CONTENTS

                                                                            Page
                                                                            ----


1.   INITIAL DEMISED PREMISES/CONDITION OF INITIAL DEMISED PREMISES.......    1
     --------------------------------------------------------------

2.   TERM.................................................................    1
     ----

3.   RENT/BASIC ANNUAL RENT...............................................    2
     ----------------------

5.   OPERATING EXPENSE INCREASES AND REAL ESTATE TAX ADJUSTMENTS..........    5
     -----------------------------------------------------------

6.   SECURITY DEPOSIT.....................................................   12
     ----------------

7.   USE..................................................................   13
     ---

9.   UPKEEP OF BUILDING...................................................   14
     ------------------

10.  ASSIGNMENT AND SUBLETTING............................................   15
     -------------------------

11.  ALTERATIONS..........................................................   19
     -----------

12.  MECHANICS' LIENS AND SIMILAR LIENS...................................   22
     ----------------------------------

13.  PERSONAL PROPERTY....................................................   22
     -----------------

14.  DELIVERIES AND MOVING OF PROPERTY BELONGING TO TENANT................   23
     -----------------------------------------------------

15.  TENANT'S EQUIPMENT...................................................   24
     ------------------

16.  SIGNS AND ADVERTISEMENTS.............................................   26
     ------------------------

17.  LANDLORD'S ACCESS....................................................   26
     -----------------

18.  SERVICES.............................................................   27
     --------

19.  RULES AND REGULATIONS................................................   28
     ---------------------

20.  DAMAGE BY TENANT.....................................................   28
     ----------------

21.  LIABILITY............................................................   29
     ---------

22.  INSURANCE............................................................   30
     ---------

23.  REQUIREMENTS FOR TENANT'S INSURANCE POLICIES.........................   31
     --------------------------------------------

24.  DAMAGE BY FIRE OR OTHER CASUALTY.....................................   32
     --------------------------------

25.  EMINENT DOMAIN.......................................................   33
     --------------


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                                       i
<PAGE>

26.  SUBORDINATION........................................................   34
     -------------

27.  ESTOPPEL CERTIFICATES................................................   36
     ---------------------

28.  BANKRUPTCY...........................................................   37
     ----------

29.  LANDLORD'S RIGHT TO CURE TENANT'S DEFAULT............................   38
     -----------------------------------------

30.  DEFAULTS AND REMEDIES................................................   39
     ---------------------

31.  REPEATED DEFAULTS....................................................   41
     -----------------

32.  SUCCESSORS...........................................................   41
     ----------

33.  AUTOMOBILE PARKING...................................................   41
     ------------------

34.  ALTERNATIVE TELEPHONE OR TELECOMMUNICATIONS PROVIDER.................   42
     ----------------------------------------------------

35.  TENANT HOLDOVER......................................................   43
     ---------------

36.  RIGHTS RESERVED BY LANDLORD..........................................   44
     ---------------------------

37.  JURY TRIAL WAIVER....................................................   45
     -----------------

38.  NOTICES..............................................................   45
     -------

39.  LIEN FOR RENT........................................................   45
     -------------

40.  LIMITATION ON LANDLORD'S LIABILITY...................................   46
     ----------------------------------

41.  COVENANTS OF LANDLORD................................................   46
     ---------------------

42.  MISCELLANEOUS........................................................   46
     -------------

43.  TENANT'S RIGHT TO RENEW..............................................
     -----------------------

44.  EXPANSION OPTIONS....................................................
     -----------------


                               TABLE OF EXHIBITS
                               -----------------


     Exhibit A    Floor Plan(s) of the Demised Premises and Expansion Spaces

     Exhibit B    Declaration as to Date of Delivery of Demised Premises and as
                  to Lease Commencement Date

     Exhibit C    Rules and Regulations

     Exhibit D    Specifications for Office Space


The Corporate Advisory Board Company Lease
June 23, 1998 Final


                                      ii
<PAGE>

     Exhibit E    Form of Tenant Estoppel Certificate

     Exhibit F    Cleaning Specifications

     Exhibit G    Guaranty

     Exhibit H    First Amendment to Deed of Trust



                            TABLE OF DEFINED TERMS
                            ----------------------
<TABLE>
<S>                                                                             <C>
Term                                                                            PAGE
----                                                                            ----

Additional Rent.................................................................  3


Adjustment Rent................................................................. 10


affiliate....................................................................... 16


Alterations..................................................................... 19


Assignment Date................................................................. 17


Assignment Notice............................................................... 17


base building systems........................................................... 14


Base Operating Expenses......................................................... 10


Base Real Estate Taxes.......................................................... 10


Basic Annual Rent...............................................................  2


Building........................................................................  1


Calendar Year...................................................................  5


control......................................................................... 16


Fiscal Year.....................................................................  5


Indemnitees..................................................................... 29


Land............................................................................  9


Landlord........................................................................  1


Lease...........................................................................  1
</TABLE>

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                                      iii
<PAGE>

<TABLE>
<CAPTION>

<S>                                                                              <C>
Lease Year......................................................................  5


Operating Expense Share.........................................................  9


Operating Expenses..............................................................  6


Provider........................................................................ 42


Real Estate Tax Share...........................................................  9


Real Estate Tax Year............................................................ 10


Real Estate Taxes...............................................................  9


Recapture Space................................................................. 18


Security Deposit................................................................ 12


Sublet Space.................................................................... 18


Subletting Date................................................................. 18


Subletting Notice............................................................... 18


subsidiary...................................................................... 16


successor partnership, limited liability company or professional corporation.... 16


Taking Date..................................................................... 34


Tenant..........................................................................  1


Tenant's Property............................................................... 23
</TABLE>

The Corporate Advisory Board Company Lease
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                                      iv
<PAGE>

                              AGREEMENT OF LEASE
                                      FOR
                     THE CORPORATE ADVISORY BOARD COMPANY

     THIS AGREEMENT OF LEASE (the "Lease") is made as of the ___ day of June,
1998, by and between The George Washington University, a non-profit corporation
chartered by an act of the Congress of the United States (hereinafter called
"Landlord"), and The Corporate Advisory Board Company, a Delaware corporation
(hereinafter called "Tenant").

     WITNESSETH, that, for and in consideration of the rents, mutual covenants
and agreements hereinafter set forth, the parties hereto do mutually agree as
follows:

1.  INITIAL DEMISED PREMISES/CONDITION OF INITIAL DEMISED PREMISES
    --------------------------------------------------------------

     (A.)  Initial Demised Premises.  Landlord has leased, and does hereby lease
         --------------------------                                            
and demise unto Tenant, and Tenant has leased and does hereby lease and hire
from Landlord as tenant of Landlord, at the rent and upon the terms, covenants
and conditions herein set forth, approximately  21,000 square feet of rentable
area on the seventh (7th) floor of the building presently known as Suite 7000,
which building is known by street address as 2000 Pennsylvania Avenue, N.W.,
Washington, D.C. 20006 and being herein referred to as the "Building". Suite
7000 is hereinafter referred to as the "Initial Demised Premises".  The Initial
Demised Premises is shown on the floor plan attached to this Lease and made a
part hereof as Exhibit A.
               ----------

     (B.) Condition of Initial Demised Premises.  Tenant agrees to accept the
          -------------------------------------                             
Initial Demised Premises in its "as is" condition existing on the date
possession of the Initial Demised Premises is delivered to Tenant by Landlord,
without Landlord being required to undertake any demolitions, removals,
alterations, improvements, decorations, repairs or modifications of the Initial
Demised Premises.  This provision shall not in any way affect any repair and
maintenance obligations of Landlord hereunder with respect to the Demised
Premises, if any.

     (C.)  Tenant Examination.  Tenant represents that it has thoroughly
           ------------------                                          
examined the Initial Demised Premises as of the date of this Lease first stated
and is aware of and accepts the existing condition of each.

     (D)   Swing Space. Landlord has leased, and does hereby lease and demise
           ------------                                                     
unto Tenant, and Tenant has leased and does hereby lease and hire from Landlord
as tenant of Landlord, upon the terms, covenants and conditions herein set
forth, approximately  4,958 square feet of rentable area on the second (2nd)
floor of the Building presently known as Suite 2500 (hereinafter called the
"Swing Space").  The Swing Space is  outlined on the floor plan attached to this
Lease and made a part hereof as Exhibit A .
                                --------- 


     (E.)  Definition of Demised Premises.  The Initial Demised Premises and any
           -------------------------------                                     
other rentable areas of the Building leased to Tenant from time to time pursuant
to the provisions of this Lease are collectively hereinafter referred to as the
"Demised Premises".


2.  TERM
    ----

     (A.) Lease Commencement Date.  The term of this Lease shall commence on the
          -----------------------                                              
Delivery Date (as hereinafter defined) of the Initial Demised Premises (the
"Lease Commencement Date").  The delivery date of the Initial Demised Premises
shall be the 1st day of July, 1998 ("Delivery Date") and except as provided
under Subparagraph (B.) of this Paragraph below,

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                                       1
<PAGE>

Landlord will deliver, and Tenant shall accept, possession of the Initial
Demised Premises on the Lease Commencement Date.

     (B.) Delay in Delivery of Initial Demised Premises and Swing Space.  In the
          -------------------------------------------------------------        
event Landlord is unable to deliver possession of Suite 7000 and/or the Swing
Space to Tenant by July 1, 1998, Landlord, its agents and employees, shall not
be liable or responsible for any claims, damages or liabilities arising in
connection therewith or by reason thereof, nor shall the validity of this Lease
be affected or Tenant be excused or released from this Lease, or its performance
hereunder.  The  Lease Commencement Date shall be extended, if necessary, to the
date Landlord delivers possession of the Initial  Demised Premises  and Tenant's
obligations pursuant to this Lease shall commence thereon. For the purposes of
this Lease, the term "Lease Commencement Date" shall also mean any extended date
of commencement of the term of this Lease as may be established pursuant to the
operation of the provisions of this Paragraph of the Lease.  If any existing
tenant of the Initial Demised Premises or occupant of the Initial Demised
Premises holds over in violation of its lease, Landlord shall promptly initiate
and pursue appropriate legal action to evict such tenant or occupant from the
Initial Demised Premises.

     (C.) Confirmation of Lease Commencement Date.  When Tenant accepts
          ---------------------------------------                     
possession of the Initial Demised Premises on the Lease Commencement Date,
Landlord and Tenant shall execute the "Declaration of Lease Commencement Date,"
attached hereto as Exhibit B, which shall specify and be controlling as to the
                   ---------                                                 
Lease Commencement Date and as to the Rent Commencement Date, as hereinafter
defined.  Actual entry by Tenant into the Initial Demised Premises shall not be
necessary to establish that the Lease Commencement Date has occurred and
Tenant's obligations hereunder have become effective.

     (D.) The Lease Expiration Date.  The initial term of this Lease shall
          -------------------------                                      
expire on June 30, 2009 (the "Lease Expiration Date"), unless the term of this
Lease shall sooner cease and expire as hereinafter provided in this Lease.

     (E)   Rent Commencement.  Tenant's first payment of Basic Annual Rent (as
           ------------------                                                
hereinafter defined) shall be due on the date that is ninety (90) days after the
Lease Commencement Date (the "Rent Commencement Date").

     (F)  Swing Space Term.  The term of this Lease for the Swing Space (i.e.,
          -----------------                                                  
unless and until such Swing Space becomes Expansion Space B as described in
Paragraph 44 hereof) shall commence on the Lease Commencement Date and continue
through June 30, 1999.  In no event shall Tenant be entitled to lease or occupy
the Swing Space after June 30, 1999 without exercising the option for Expansion
Space B set forth in Paragraph 44 hereof, and should Tenant continue in
occupancy after June 30, 1999 without having exercised Tenant's option for
Expansion Space B, Tenant shall be considered to be a tenant at will and the
provisions of Paragraph 35 TENANT HOLDOVER shall apply.
                           ---------------            


3.  RENT/BASIC ANNUAL RENT
    ----------------------

     (A.) Rent.  Tenant hereby covenants and agrees to pay to Landlord, as
          ----                                                           
consideration for making this Lease with Tenant, rent of the kind and nature
hereinafter prescribed in this Lease.  Rent shall include, but is not limited
to, Basic Annual Rent, as increased pursuant to this Lease (as hereinafter
defined), Adjustment Rent (as hereinafter defined), any modification to Basic
Annual Rent or Adjustment Rent, any increases due to increases or decreases in
the size of the Demised Premises, and any sums, charges, expenses and costs
identified in this Lease as to be


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June 23, 1998 Final

                                       2
<PAGE>

paid by Tenant to Landlord (with all rent, other than Basic Annual Rent [and any
modifications thereto] being collectively defined and hereinafter referred to as
"Additional Rent").

     (B.) Basic Annual Rent/Basic Monthly Rent.  In keeping with Tenant's
          ------------------------------------                          
covenant and commitment to pay rent, Tenant agrees to pay a basic annual rent
for the leasing of the Initial Demised Premises (other than the Swing Space) of
Thirty-two and 50/100th Dollars ($32.50) per rentable square foot, subject to
annual increases during the term of this Lease as set forth hereinbelow, (such
rent, as adjusted is hereinafter referred to as  "Basic Annual Rent"). Basic
Annual Rent shall be due and payable in equal monthly installments.  Each of
said monthly installments of Basic Annual Rent are hereinafter called "Basic
Monthly Rent". Every installment of Basic Monthly Rent shall be due and payable
without demand and shall not be subject to setoff, deduction or counterclaim,
except if and as otherwise provided herein. Installments of Basic Monthly Rent
shall be due and payable in advance on or before the first day of each calendar
month during the term hereof, commencing on the Rent Commencement Date. If the
Rent Commencement Date occurs on a day other than the first day of a calendar
month, then the first installment of Basic Monthly Rent  paid by Tenant shall be
prorated based upon the number of days in such partial month and Tenant shall be
credited with any overpayment.

     It is agreed by Landlord and Tenant that all Basic Monthly Rent and
Additional Rent otherwise due on the Swing Space shall be abated for the period
from July 1, 1998 through June 30, 1999 or, if the Lease Commencement Date with
respect to the Swing Space is not July 1, 1998, then for a period commencing on
the Lease Commencement Date and continuing for a period of twelve (12) months
from such Lease Commencement Date. It is agreed by Landlord and Tenant that all
Basic Monthly Rent otherwise due for Suite 7000 and for the Mandatory Expansion
Space, as hereinafter defined, shall be abated for the months of July and
August, 2000, or if the Lease Commencement Date is not July 1, 1998, then for
the first two (2) months of the third Lease Year.

     Basic Annual Rent per rentable square foot shall be subject to adjustment
and escalation effective as of the first day of each Lease Year starting with
the second Lease Year, (excluding, however, the sixth Lease Year), by an amount
equal to two percent (2%) of the per-square-foot Basic Annual Rent in effect for
the immediately preceding and expiring Lease Year.  In lieu of a 2% escalation
in the sixth Lease Year,  the per-square-foot Basic Annual Rent for the sixth
Lease Year shall be equal to the per-square-foot Basic Annual Rent in effect for
the fifth (5th) Lease Year plus an amount equal to Two Dollars ($2.00) per
rentable square foot.

     Accordingly, as computed, Basic Annual Rent and the resulting Basic Monthly
Rent for the Initial Demised Premises shall be as follows:


<TABLE>
<CAPTION>

                                 Basic Annual Rent     Basic Annual     Basic Monthly
         Lease Year               Per Square Foot          Rent             Rent
------------------------------  -------------------  ---------------  ---------------
<S>                             <C>                  <C>              <C>

              1                       $32.50             $682,500        $56,875
------------------------------  -------------------  ---------------  ---------------

              2                       $33.15             $696,150        $58,012.50
------------------------------  -------------------  ---------------  ---------------

              3                       $33.81             $710,010        $59,167.50
------------------------------  -------------------  ---------------  ---------------

              4                       $34.49             $724,290        $60,357.50
------------------------------  -------------------  ---------------  ---------------

              5                       $35.18             $738,780        $61,565
------------------------------  -------------------  ---------------  ---------------

              6                       $37.18             $780,780        $65,065
------------------------------  -------------------  ---------------  ---------------
</TABLE>



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                                       3
<PAGE>

<TABLE>
<CAPTION>

<S>                             <C>                  <C>              <C>

              7                       $37.92             $796,320        $66,360
------------------------------  -------------------  ---------------  ---------------

              8                       $38.68             $812,280        $67,690
------------------------------  -------------------  ---------------  ---------------

              9                       $39.45             $828,450        $69,037.50
------------------------------  -------------------  ---------------  ---------------

             10                       $40.24             $845,040        $70,420
------------------------------  -------------------  ---------------  ---------------

             11                       $41.04             $861,840        $71,820
------------------------------  -------------------  ---------------  ---------------
</TABLE>


     (C.) Payment Instructions.  All rent shall be paid by check (subject to
          --------------------                                             
collection) made payable to the order of " The George Washington University" and
shall be delivered to "LaSalle Partners Management Services, Inc., P.O. Box
71015, Chicago, IL 60694-1015," or to such other party or address as Landlord
may from time to time designate in writing.

     (D.) Certified/Cashier's Check.  If Tenant is delayed or in default in
          -------------------------                                       
making any payment of rent of any kind and nature more than once during any
Lease Year during the term of this Lease, then Landlord at its option may
require that all future payments of rent thereafter be made by certified or
cashier's check, payable to Landlord.  This requirement shall be in addition to
and not in limitation of any remedies available to Landlord under this Lease for
Tenant's failure to timely and properly pay rent.


4.  MANDATORY EXPANSION OF INITIAL DEMISED PREMISES.
    ------------------------------------------------

     (A.)  Obligation.
           -----------

          Subject to the provisions of Subparagraph (B.) of this Paragraph,
Tenant shall be obligated to lease from Landlord, and Landlord shall be
obligated to lease to Tenant, approximately 6,765 square feet of rentable area
on the seventh (7th) floor of the Building presently known as Suite 7400 and
approximately 37,701 square feet of rentable area on the sixth (6th) floor of
the Building presently known as Suite 6000 (collectively, the "Mandatory
Expansion Space").  The Mandatory Expansion Space is outlined on the floor plan
attached to this Lease and made a part hereof as Exhibit A. If any existing
                                                 ---------                
tenant of the Mandatory Expansion Space or occupant of the Mandatory Expansion
Space holds over in violation of its lease, Landlord shall promptly initiate and
pursue appropriate legal action to evict such tenant or occupant from the
Mandatory Expansion Space.

     (B.)  Commencement Date.
           ------------------

          (i) The commencement date of this Lease with regard to the Mandatory
Expansion Space shall be March 23, 1999, or such later date as Landlord shall be
able to deliver the Mandatory Expansion Space to Tenant (in either case, the
"Mandatory Expansion Space Lease Commencement Date").

          (ii)  The term of this Lease with regard to the Mandatory Expansion
Space shall commence on the date Landlord delivers possession of the Mandatory
Expansion Space to Tenant ("Mandatory Expansion Space Delivery Date"), but in no
event shall the Mandatory Expansion Space Delivery Date be earlier than March
23, 1999, without Tenant's prior approval.

          (iii)  The lease termination date with respect to the Mandatory
Expansion Space will be the same as the Lease Expiration Date for the Initial
Demised Premises.


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                                       4
<PAGE>

     (C.)  Conditions of the Leasing of the Mandatory Expansion Space by Tenant.
           ---------------------------------------------------------------------

          Tenant shall lease the Mandatory Expansion Space from Landlord subject
to and upon the following conditions, and where not in conflict with the
following, on the same terms and conditions as the Initial Demised Premises:

          (i)  Tenant shall accept the Mandatory Expansion Space in "AS IS"
condition, without Landlord being required to undertake any demolition,
removals, alterations, improvements, decorations, repairs or modifications of
the Mandatory Expansion Space. This provision shall not in any way affect any
repair and maintenance obligations of Landlord hereunder with respect to the
Mandatory Expansion Space, if any.

          (ii) Tenant shall pay to Landlord, as Basic Annual Rent for the
Mandatory Expansion Space ("Mandatory Expansion Space Rent") an amount equal to
the product of the number of square feet of rentable area attributable to the
Mandatory Expansion Space, multiplied by the then-applicable per-square-foot
Basic Annual Rent attributable to the Initial Demised Premises in effect for
each Lease Year of the remainder of the term, beginning with the Lease Year in
which the Mandatory Expansion Space Rent Commencement Date (as hereinafter
defined) occurs and further, to pay that Mandatory Expansion Space Rent in equal
monthly installments to Landlord with the Basic Monthly Rent paid for the
Initial Demised Premises.

          (iii) Tenant shall commence to pay Mandatory Expansion Space Rent, in
advance, from and after three (3) months after the Mandatory Expansion Space
Lease Commencement Date (the "Mandatory Expansion Space Rent Commencement
Date").

          (iv) Tenant shall commence to pay Adjustment Rent for the Mandatory
Expansion Space from and after the Mandatory Expansion Space Rent Commencement
Date, and the percentage of the Tenant's Operating Expense Share and the
percentage of the Tenant's Real Estate Tax Share shall be increased to reflect
the addition of the Mandatory Expansion Space to the Initial Demised Premises in
accordance with the calculation of such percentages set forth in Paragraph 5 of
the Lease entitled "OPERATING EXPENSE INCREASES AND REAL ESTATE TAX
                    -----------------------------------------------
ADJUSTMENTS",  such revised percentages to become effective as of the Mandatory
--------------                                                                
Expansion Space Rent Commencement Date, with appropriate pro rata adjustments in
Adjustment Rent being made in the Lease Year in which the Mandatory Expansion
Space Rent Commencement Date occurs.

5.  OPERATING EXPENSE INCREASES AND REAL ESTATE TAX ADJUSTMENTS
    -----------------------------------------------------------

     (A.) Definitions.  As used in this Lease, the terms listed below shall have
          -----------                                                          
the  meanings indicated, namely:

          (i) "Calendar Year" shall mean each consecutive twelve (12) calendar
          month period, January 1st through the succeeding December 31st, of any
          year in which this Lease is in effect.

          (ii) "Fiscal Year" shall mean the period July 1st of one Calendar Year
          through June 30th of the next Calendar Year, being the fiscal year of
          the Building, or such other twelve (12) calendar month period,
          including a Calendar Year, as Landlord may determine from time to time
          during the term of this Lease.

          (iii)  "Lease Year" shall mean each consecutive twelve (12) calendar
          month period commencing on the Lease Commencement Date, or if the
          Lease


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                                       5
<PAGE>

          Commencement Date is not the first day of a calendar month, then
          commencing on the first day of the calendar month next following the
          Lease Commencement Date.

          (iv) "Operating Expenses" shall mean any and all expenses reasonably
          allocated by Landlord to the office areas of the Building (as
          distinguished from the areas of the Building designated from time to
          time by Landlord as retail areas of the Building) incurred in a Fiscal
          Year in connection with the operation, maintenance, servicing, repair
          and improvement of the Building and its appurtenances, but net of any
          discounts, credits, rebates or reimbursements to Landlord. Operating
          Expenses shall be determined in accordance with generally accepted
          accounting principles, ("GAAP") consistently applied and modified as
          necessary to reflect customary property management practices and the
          specific provisions of this paragraph (iv).   By way of example, but
          without limitation, Operating Expenses shall include, but are not
          limited to, any and all of the following:

               (a)  salaries, wages, medical, surgical and general welfare
                    benefits (including also group life insurance and pension
                    payments for employees of Landlord or Landlord's agent or
                    agents engaged in the operation, maintenance, servicing or
                    repair of the Building);

               (b)  payroll taxes;

               (c)  premiums and payments related to workmen's compensation
                    insurance;

               (d)  license and permit fees and charges;

               (e)  electricity charges;

               (f)  costs and expenses for repairs and maintenance;

               (g)  utility taxes;

               (h)  water and sewer charges;

               (i)  natural gas charges (if any);

               (j)  oil and other fuels charges;

               (k)  premiums and other charges for insurance provided and
                    maintained by Landlord, including casualty and liability
                    insurance;

               (l)  charges for security services;

               (m)  fees and charges for char and cleaning services;

               (n)  costs of operating supplies for the Building, including
                    cleaning supplies and equipment;

               (o)  costs of uniforms and dry cleaning and laundering;

               (p)  costs related to window cleaning;



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                                       6
<PAGE>

               (q)  costs related to snow removal;

               (r)  costs and expenses of repair and maintenance of common areas
                    in or about the Building and the Land, including but not
                    limited to sidewalks, driveways, parking facilities, vaults,
                    roadways, grounds, and public spaces;

               (s)  management and service provider fees actually incurred by
                    Landlord (but as to property management fees,  not to exceed
                    market rates for such services for first-class office
                    buildings in downtown Washington, D.C.) ;

               (t)  costs and expenses of service or management contracts with
                    independent contractors;

               (u)  fees and expenses of accountants and attorneys, including
                    but not limited to those incurred to reduce or contest
                    Operating Expenses or Real Estate Taxes;

               (v)  costs and expenses incurred for telephone, telegraph,
                    postage, stationery, supplies and other materials required
                    for or related to the operation of the Building, including
                    those of any management office supporting the Building;

               (w)  the cost of capital improvements to the Building and
                    appurtenant improvements made by Landlord (i) for the
                    purpose of complying with governmental laws, rules,
                    regulations or order arising subsequent to the date of this
                    Lease first hereinabove stated, or (ii) which are reasonably
                    determined by third party consultants hired by Landlord to
                    be likely to reduce Operating Expenses, provided that the
                    cost of each such capital improvement, together with
                    financing charges if the improvement is not financed by
                    borrowing, shall be amortized in constant annual payments
                    over the useful life of the improvement, and only the amount
                    of that annual payment shall be included as Operating
                    Expenses for any Fiscal year; and,

               (x)  any other expenses or charges of any nature whatsoever,
                    whether or not herein mentioned, which would be included as
                    operating expenses of a mixed use, commercial office
                    building in accordance with generally accepted accounting
                    and management principles with respect to operation of
                    first-class office buildings in the Washington, D.C.,
                    Metropolitan Area.

          Operating Expenses may, in Landlord's sole discretion, include
          payments made to entities related to Landlord, or in which Landlord
          may have a direct or indirect interest, to reimburse such entities (as
          determined by Landlord using commercially reasonable principles) for
          the proportionate use by Landlord within the Building of equipment
          owned or personnel employed by such entities which are used both by
          such entities and Landlord.

          Operating Expenses shall not include any of the following: (a)
          painting or decorating areas of the Building other than public areas;
          (b) interest and amortization


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       7
<PAGE>

          on mortgages; (c) depreciation of the Building (but not any
          amortization of capital improvements and interest thereon as provided
          for above); (d) ground rent, if any; (e) salaries and other
          compensation paid to officers or executives of Landlord or to any
          partner, principal or owner of the entity comprising Landlord; (f)
          income taxes imposed upon the net income of Landlord from the
          operation of the Building; (g) the costs of alterations, capital
          improvements and other items which under generally accepted accounting
          principles are properly classified as capital expenditures (except to
          the extent otherwise provided in Subparagraph 5(A.)(iv)(w)); (h) any
          tenant work performed or alteration of space leased to Tenant or other
          tenants or occupants of the Building, whether such work or alteration
          is performed for the initial occupancy by such tenant or occupant or
          thereafter; (i) any cash or other consideration paid by Landlord on
          account of, with respect to or in lieu of the tenant work or
          alterations described in (h) above; (j) interest and amortization of
          indebtedness or any costs of financing or refinancing, depreciation or
          ground rent; (j) management fees in excess of the amount permitted
          under Subparagraph 5(A.)(iv)(s); (k) leasing commissions and
          advertising (other than advertising for building employees) and
          promotional expenses related to leasing space in the Building; (l)
          "takeover lease expenses" (i.e., expenses incurred by Landlord with
                                     ----
          respect to leases entered into by tenants of the Building for space
          which such tenants vacated in another building in connection with the
          leasing of space in the Building); (m) any amounts payable by Landlord
          by way of indemnity or for damages or which constitute a fine,
          interest or penalty which payments were not triggered or caused,
          directly or indirectly, by the actions or inactions of Tenant; (n) any
          cost representing an amount paid for services or materials to a
          person, firm or entity related to Landlord or any general partner of
          Landlord to the extent such amount exceeds the maximum amount that
          would be paid in the marketplace for such services or materials to an
          unrelated third party for the identical level and nature of services
          or materials; (o) costs for which Landlord actually receives
          reimbursement from insurance, condemnation awards or any other source
          and expenses for repairs and other work caused by fire, windstorm or
          other casualty required to be insured under this Lease; (p) any
          expenses incurred by Landlord as a result of asbestos in the Building
          or on or about the Land or suspected to be in the Building or on or
          about the Land; and (q) legal, investigative, and court costs in
          connection with the enforcement by Landlord of leases to tenants in
          the Building. In addition, to the extent that the costs of performing
          additional services (including operation of the Building beyond the
          days and hours specified in Paragraph 15 (A.) and start-up time
          related thereto) or the costs of installations to or for tenants other
          than Tenant are reimbursed to Landlord by such tenants, such costs
          shall not be included in Operating Expenses.

               If during all or part of any Fiscal Year, including the Fiscal
          Year ending June 30, 1999,  Landlord shall not furnish any particular
          item of work or service (which would constitute an item of Operating
          Expenses hereunder) to at least ninety-five percent (95%) of the
          rentable area of the Building designated by Landlord as office space,
          because (a) less than all of the space then designated for office
          space of the Building is occupied, or (b) such item of work or service
          is not desired or required by any tenant of the office space, or (c)
          any tenant of the office space is itself obtaining and providing such
          item of work or service, then an adjustment shall be made in computing
          the Operating Expenses for such Fiscal Year so that the Operating
          Expenses shall be increased for such Fiscal Year to the amount that
          would have been reasonably incurred had Landlord provided such item of
          work or service to ninety-five percent (95%) of the rentable area of
          the Building designated by Landlord as office space for the entire
          Fiscal Year.


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June 23, 1998 Final

                                       8
<PAGE>

          (v) "Operating Expense Share" shall mean Tenant's proportionate share
          of increases in Operating Expenses (as hereinafter defined);
          representing the ratio that the rentable area of the Demised Premises
          bears to the total rentable area of all office area in the Building
          from time to time, which total rentable area of office area of the
          Building excludes the area of any storage areas located outside any
          Demised Premises leased to tenants in the Building and the area of the
          garage within the Building.  As of the date of this Lease first
          hereinabove stated, Tenant's Operating Expense Share will be seven and
          one thousand seven hundred ninety-three ten-thousandths percent
          (7.1793%) and Tenant's Operating Expense Share will increase to
          twenty-two and three thousand eight hundred eight ten-thousandths
          percent (22.3808%) from and after the Mandatory Expansion Space Rent
          Commencement Date.  Tenant's Operating Expense Share will increase
          upon the addition of any of Expansion Space A, Expansion Space B, or
          Expansion Space C, all as provided in Paragraph 44 hereof.

          (vi) "Real Estate Tax Share" shall mean Tenant's proportionate share
          of increases in Real Estate Taxes (as hereinafter defined),
          representing the ratio that the rentable area of the Demised Premises
          bears to the total rentable area of all office and retail areas
          contained in the Building from time to time, which total rentable area
          of office and retail areas of the Building excludes the area of any
          storage areas located outside any Demised Premises leased to tenants
          in the Building and the area of the garage within the Building.  As of
          the date of this Lease first herein above stated, Tenant's Real Estate
          Tax Share will be five and seven thousand nine hundred fifty-one ten-
          thousandths percent (5.7951%) and shall increase to eighteen and six
          hundred fifty-eight ten-thousandths percent (18.0658%) from and after
          the Mandatory Expansion Space Rent Commencement Date.  Tenant's Real
          Estate Tax Share will increase upon the addition of any of Expansion
          Space A, Expansion Space B, or Expansion Space C, all as provided in
          Paragraph 44 hereof.

          (vii)  "Real Estate Taxes" shall mean all taxes, rates and
          assessments, general and special and including also any increases in
          tax rate and/or in assessed valuation, which are now or at any time(s)
          hereafter levied, assessed or imposed with respect to the Building and
          all land related or appurtenant thereto (the "Land"), and/or upon
          Landlord's leasehold interest (if any) in the said Land, to the extent
          same apply to a Real Estate Tax Year (or part thereof occurring during
          the term of this Lease).  Real Estate Taxes shall include without
          limitation, real estate taxes, personal property taxes applicable to
          the personalty in the Building, any and all unincorporated and other
          business license and/or franchise taxes (other than such taxes based
          upon Landlord's net income), public space rentals, including but not
          limited to vault rentals, any taxes, assessments or other levies which
          may at any time be imposed and/or collected by any federal, state,
          county, municipal, quasi-governmental or corporate entity in respect
          of bus, subway or other public transportation facilities operating in
          the metropolitan area of the District of Columbia, and including also
          any assessment or levy for any business improvement district duly
          formed in accordance with applicable law, and any tax assessment or
          other charges in the nature of a sales, use or other tax upon
          Landlord, the Demised Premises, the Building, the Land and/or the
          rents payable hereunder (except income taxes, franchise taxes
          calculated upon Landlord's net income, estate or inheritance taxes of
          Landlord).  If the system of real estate taxation shall be altered or
          varied and any new tax or levy shall be levied or imposed on the
          Building, and/or Land and/or Landlord, in addition to or in
          substitution for real estate taxes


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       9
<PAGE>

          and/or personal property taxes presently levied or imposed on
          immovables in the District of Columbia, and including also without
          limitation any taxes on rents, then any such new tax or levy shall be
          included within the term "Real Estate Taxes". If any Real Estate Tax
          is levied or assessed in such a manner that the amount thereof
          required to be paid by Tenant hereunder in respect of its Real Estate
          Tax Share is not ascertainable because such tax relates to one or more
          properties other than the Building or to rents received by Landlord in
          addition to those received from the Building, then Tenant's Real
          Estate Tax Share of said items to be paid by Tenant forming a part of
          the Real Estate Taxes shall be reasonably determined by Landlord. If
          any Real Estate Taxes levied against the Land, Building or
          improvements covered hereby or the rents reserved therefrom, shall be
          evidenced by improvement bonds or other bonds, or in any other form,
          which may be paid in annual installments, Landlord shall include the
          same in Real Estate Taxes based upon the maximum period permitted by
          law for payment of such installments and only the amount payable for a
          Real Estate Tax Year elapsing during the term of this Lease shall be
          included as Real Estate Taxes for purposes of this definition.

          (viii)  "Real Estate Tax Year" shall mean the fiscal year of the
          District of Columbia being October 1st of one Calendar Year through
          September 30th of the next succeeding Calendar Year, or such other
          twelve (12) calendar month period as Landlord may determine from time
          to time during the term of this Lease, including such other period as
          may be defined as the fiscal year of the District of Columbia from
          time to time during the term of this Lease.  The term "Real Estate Tax
          Year" shall include any period of adjustment which may result from a
          change in designation of the period identified by the District of
          Columbia as its fiscal year.


     (B.) Obligations for Adjustment Rent.  During the term of this Lease and
          -------------------------------                                   
any renewals or extensions thereof, Tenant covenants and agrees to pay to
Landlord, as part of Additional Rent, (i.) Tenant's Operating Expense Share of
any Operating Expenses in excess of the Operating Expenses incurred during the
Fiscal Year elapsing between July 1, 1998 and June 30, 1999 ("Base Operating
Expenses"), and (ii.) Tenant's Real Estate Tax Share of Real Estate Taxes in
excess of the Real Estate Taxes payable for the Real Estate Tax Year 1999 (i.e.,
                                                                           ----
October 1, 1998 through September 30, 1999) ("Base Real Estate Taxes"),
provided, however, that during any renewal or extension of this Lease, the Base
Operating Expenses and Base Real Estate Taxes shall be modified to reflect the
Fiscal Year and Real Estate Tax Year during which such renewal or extension
commences, or such other Fiscal Year and Real Estate Tax Year as Landlord and
Tenant agree should apply.  The payments called for above as (i) and (ii) in
this Subparagraph (B.) are hereinafter sometimes collectively referred to as
"Adjustment Rent."  Tenant shall make the payments of Adjustment Rent called for
in this Subparagraph (B.) commencing on July 1, 1999 and shall make such
payments within thirty (30) days after each and every request therefor from
Landlord.  Copies of the appropriate bills for Real Estate Taxes, together with
the statement of Operating Expenses of the Building for the Fiscal Year in
reasonable detail prepared by Landlord or Landlord's accountants, covering said
Adjustment Rent shall be furnished to Tenant as soon as is reasonably
practicable following Landlord's billing of such Adjustment Rent under this
Subparagraph (B.), and unless timely contested by Tenant pursuant to Paragraph
5(D) below, shall be deemed conclusive and binding on the parties.  Tenant's
obligation to pay Adjustment Rent shall survive the expiration or earlier
termination of this Lease with regards to payments thereof covering any portion
of the term of this Lease through the date of expiration or termination of the
Lease.


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June 23, 1998 Final

                                       10
<PAGE>

     (C.) Estimates by Landlord.  Landlord may from time to time during the term
          ---------------------                                                
hereof (and more frequently than once during any Lease Year) deliver to Tenant a
written estimate by Landlord of the amount of annual Adjustment Rent which
Landlord may estimate and determine will be payable by Tenant during any ensuing
Fiscal Year (or portions of a Fiscal Year).  Such estimated sum is hereinafter
called the "Estimated Adjustment Rent".  Commencing on the first day of the
calendar month immediately following the month in which such statement of
Estimated Adjustment Rent is tendered, and on the first day of each and every
calendar month thereafter until the next such statement, Tenant shall pay to
Landlord (in addition to and with Basic Monthly Rent), as Additional Rent, a sum
as specified by Landlord which is equal to one-twelfth (1/12th) of said
Estimated Adjustment Rent, such payments to continue to be due and payable until
further notice from Landlord.  At the end of each Fiscal Year, Landlord shall
furnish to Tenant, within a reasonable time after the end of such Fiscal Year,
an annual statement setting forth in reasonable detail the actual amount of the
annual Adjustment Rent due and payable by Tenant for the immediately preceding
Fiscal Year in which such monthly installments of Estimated Adjustment Rent were
paid by Tenant pursuant to this Subparagraph (C.).  Thereafter Landlord and
Tenant shall then make an appropriate adjustment of said Estimated Adjustment
Rent paid by Tenant for the then expired Fiscal Year within thirty (30) days
after delivery of such statement, accomplished as applicable either by Tenant's
payment to Landlord of any deficiency, or, at Landlord's option, by Landlord's
refund or credit toward future installments of Basic Monthly Rent in case of any
overpayment of Adjustment Rent by Tenant.

     (D.) Within ninety (90) days after delivery of an annual Operating Expense
statement, Tenant shall notify Landlord  whether Tenant will examine Landlord's
books and records with respect to such Operating Expense statement.  If Tenant
so notifies Landlord then Tenant and its representatives shall have the right,
at Tenant's expense, upon reasonable prior notice to Landlord during normal
business hours, to examine Landlord's books and records relating to the
operation of the Building for the three (3) most recent Fiscal Years to verify
matters in the Operating Expense statement(s) for such three most recent Fiscal
Years, provided however, that Tenant may review the books and records and
request an adjustment in Tenant's Adjustment Rent only once for each Fiscal Year
being reviewed by or on behalf of Tenant and such review shall not occur more
than one time in any Lease Year.  If as a result of such examination, Tenant
disputes any such Operating Expense statement, Tenant shall notify Landlord that
it disputes such Operating Expense statement setting forth the reasons therefor
(a "Notice of Dispute").  If Landlord shall have overstated Adjustment Rent for
any Fiscal Year, Landlord shall promptly refund such excess to Tenant. If such
Adjustment Rent shall have been overstated by an amount in excess of five
percent (5%), Landlord shall reimburse Tenant for the reasonable, actual, out-of
pocket cost of such examination.  If Landlord shall have understated Adjustment
Rent for any Fiscal Year, Tenant shall promptly pay such understated amount  to
Landlord. Tenant agrees to maintain all information it receives from Landlord or
Landlord's agents in connection with Tenant's examination of the books and
records in strictest confidence and shall not reveal the same to any other
persons or entities except to such accounting or real estate brokerage firms or
attorneys which Tenant has employed to assist Tenant in the review of such books
and records, which firms shall, prior to receiving any information from such
books and records, execute an agreement with Tenant and Landlord agreeing to
maintain all such information in confidence.  In the event that Tenant employs
any persons or entities to review the books and records in accordance with
Tenant's rights stated herein, such persons or entities shall not be compensated
for their work for Tenant on a contingency basis or in any manner which is based
upon the amount of the discrepancies or errors found in the books and records.
In the event that Adjustment Rent is found not to be overstated, then Tenant
shall immediately pay Landlord an administrative fee of $500 for the costs and
expense incurred by Landlord and Landlord's personnel in making such books and
records available for review and in handling any other requests by Tenant or
Tenant's agents in connection with the review of the books and records.


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       11
<PAGE>

6.  SECURITY DEPOSIT
    ----------------

     (A.) Delivery.  Simultaneous with the delivery by Tenant of this Lease
          --------                                                        
fully executed by Tenant, Tenant shall deposit with Landlord the sum of One
Million Three Hundred Thousand Dollars ($1,300,000) as security for Tenant's
performance under this Lease (the "Security Deposit").  The Security Deposit
shall be in the form of an unconditional, irrevocable letter of credit payable
at sight to Landlord in form and substance and from a financial institution
acceptable to Landlord in its reasonable discretion.  Such letter of credit
shall be assignable by Landlord, as beneficiary, and any successor to Landlord.
Such letter of credit shall have a term of not less than one year and shall be
automatically renewed without notice from Landlord or Tenant to the issuer at
least forty-five days prior to each one year anniversary of the letter of
credit's issuance.  In the event that Tenant has not provided Landlord with a
replacement letter of credit within thirty (30) days prior to the expiration of
the letter of credit then being held by Landlord, Landlord shall draw down the
letter of credit and shall hold the sum thereby received  in a non-interest
bearing account, provided, however, that if Tenant delivers a replacement letter
of credit, in form and substance acceptable to Landlord in its sole discretion
and in compliance with the provisions of this Paragraph 6, and Tenant is not
otherwise in default of its obligations under this Lease, then Landlord shall
return to Tenant the cash then on deposit in such non-interest bearing account.
If Tenant is in default of its obligations under this Lease at the time Tenant
delivers a replacement letter of credit as aforesaid, then only after such
default has been cured to Landlord's full satisfaction during the period
provided herein for the curing of such default, shall Landlord return the cash
then on deposit in a non-interest bearing account to Tenant.  Provided that
Tenant is not then in default and has not been in default during the term
hereof, the letter of credit may be reduced to One Million Forty Thousand
Dollars ($1,040,000) on the Burnoff Date, as such term is defined in the
Guaranty of even date herewith from The Advisory Board Company to Landlord, a
copy of which is attached hereto and incorporated herein by this reference as
Exhibit G and provided that Tenant is not then in default and has not been in
---------                                                                   
default during the term hereof, and further provided that the Burnoff Date has
occurred, then the letter of credit may be further reduced to Six Hundred Fifty
Thousand Dollars ($650,000) on the one year anniversary of the Burnoff Date.  In
the event that Tenant is in default on the date upon which the letter of credit
would otherwise have been reduced in amount, and the cure period for such
default by Tenant, if any, has not yet expired, then in the event that Tenant
cures such default within any applicable cure period, Tenant may thereafter
reduce the amount of the letter of credit to an amount which it would have been
absent the default by Tenant on the applicable date for reduction thereof.  From
and after the one year anniversary of the Burnoff Date,  Tenant shall maintain
the letter of credit in the amount of $ 650,000 through the term of this Lease.
The letter of credit shall be security for Tenant's payment and performance of
all Tenant's obligations, covenants, conditions and agreements under this Lease.

     (B.) Availability to Landlord.  In the event Tenant fails to perform its
          ------------------------                                          
obligations, including but not limited to accepting possession of the applicable
portion of the Demised Premises  on the  Lease Commencement Date and the
Mandatory Expansion Space Lease Commencement Date as provided for herein,
Landlord shall have the right, but shall not be obligated, to apply all or any
portion of the Security Deposit to cure any default by Tenant.  The use of the
Security Deposit by Landlord, as aforesaid, shall not excuse Tenant's liability
for defaults hereunder nor limit Landlord's remedies.  If Landlord so applies
any or all of the Security Deposit, Tenant shall be obligated to promptly
restore the Security Deposit to its original amount, within five (5) days after
receiving a request from Landlord to do so.  The Security Deposit shall not be
deemed liquidated damages and Landlord may apply all or a portion of the
Security Deposit to reduce Landlord's damages of any kind and nature (including
but not limited to court costs and reasonable


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       12
<PAGE>

attorneys' fees). Such application of the Security Deposit shall not preclude
Landlord from recovering from Tenant all additional damages incurred by
Landlord.

     (C.) Return of Security Deposit.  If Tenant fully and faithfully complies
          --------------------------                                         
with all terms and conditions of this Lease, the Security Deposit shall be
returned to Tenant within thirty (30) days following the expiration of the term
of this Lease and Tenant's surrender of the Demised Premises in accordance with
the terms of this Lease.

     (D.) Sale or Transfer.  In the event of the sale or transfer of Landlord's
          ----------------                                                    
interest in the Building, Landlord shall transfer the Security Deposit to such
purchaser or transferee, in which event Tenant shall be entitled to look to the
new party identified as Landlord for the return of the Security Deposit, and
Landlord shall thereupon be released from all liability to Tenant for the return
of the Security Deposit.  Furthermore no holder of a mortgage or deed of trust
to which this Lease is subordinate shall be responsible for the Security Deposit
unless such mortgagee or holder of such deed of trust shall have actually
received or obtained control over the Security Deposit.


7.  USE
    ---

     (A.) Permitted Use.  Tenant shall use and occupy the Demised Premises for
          -------------                                                      
general office use and for no other use or purpose whatsoever without the prior
written consent of Landlord.  Tenant may not use the Demised Premises for any
use which will cause  Landlord to have to modify the Building common areas to
comply with The Americans With Disabilities Act, as it may be amended (the
"ADA") or other similar laws, rules, ordinances and regulations which may
hereinafter be enacted.   Tenant hereby covenants and agrees, on behalf of
itself and its assigns, subtenants, contractors and invitees, not to obstruct or
interfere with the rights of other tenants of the Building, and not to injure or
annoy them or those having business with them.  Tenant may not use or permit the
Demised Premises or any part thereof to be used for any disorderly, unlawful or
extra hazardous purpose nor for any other purpose than herein specified.  Tenant
shall specifically not manufacture any commodity within the Demised Premises.
Tenant shall not store or use, or permit others to store or use, within the
Demised Premises any hazardous or toxic substances or hazardous or toxic wastes
or materials, as defined under applicable Federal and/or local law in violation
of any such law.

     (B.) Compliance.  Tenant shall comply with all laws, ordinances, rules,
          ----------                                                       
orders and regulations of all government authorities and of the Board of Fire
Underwriters (and any successor thereto) at any time promulgated and in force,
attributable to the use, or manner of use by Tenant of the Demised Premises, or
any part thereof.  To the extent after the date of this Lease that Tenant's use
or uses of the Demised Premises, or Tenant's manner of operation creates a need
or requirement under applicable statute, ordinance or regulation of any
governmental authority to modify or alter the Demised Premises, supporting
facilities, or access thereto, Tenant shall be fully responsible for the costs
to undertake such changes, and to obtain Landlord's approval (such approval not
to be unreasonably withheld, delayed or conditioned) to undertake such changes
pursuant to the Paragraph of this Lease entitled "ALTERATIONS".
                                                  ----------- 

     (C.) Certificate of Occupancy.  Tenant specifically shall be required to
          ------------------------                                          
obtain a Certificate of Occupancy from the District of Columbia for Tenant's use
and occupancy of the Building at or prior to the date Tenant occupies the
Demised Premises for its business purposes.



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June 23, 1998 Final

                                       13
<PAGE>

8.  UPKEEP OF DEMISED PREMISES
    --------------------------

     Tenant shall keep the Demised Premises and related appurtenances, including
without limitations, doors and windows, the fixtures and equipment therein
clean, safe and sanitary, in good order and condition, in compliance with all
applicable laws, ordinances and regulations of any governmental authority having
jurisdiction over the Building, shall take good care thereof, and shall suffer
no waste or injury thereto.  At the expiration or earlier termination of the
term of this Lease, Tenant shall surrender the Demised Premises broom clean and
in the same order and condition in which they were on the Lease Commencement
Date or the Mandatory Expansion Space Lease Commencement Date, as applicable,
ordinary wear and tear and damage by the elements excepted.  To the extent that
Tenant's manner of operation or use of the Demised Premises (which Tenant agrees
shall be general office use) creates a need or requirement under applicable law,
ordinance or regulation of any governmental authority for special cleaning,
maintenance, repair and/or modification of the Demised Premises, its fixtures or
improvements, Tenant shall be fully responsible to undertake such cleaning,
maintenance, repair or modification at its sole cost.



9.  UPKEEP OF BUILDING
    ------------------

     Subject to the provisions of this Lease entitled "DAMAGE BY TENANT,"
                                                       ---------------- 
Landlord agrees that it will deliver and keep the Base Building Systems of the
Building (as hereinafter defined) and all structural elements thereof in good
working order and condition, in accordance with the standards customarily
employed by other landlords of similar and comparable first class office
buildings located within the central business district of Washington, D.C., and
the costs thereof incurred by Landlord shall be deemed to be an element of
Operating Expenses of the Building except as otherwise provided in Paragraph
5(A.).  For the purposes of this Paragraph, the term "Base Building Systems"
shall be deemed to include, but not be limited to, the roof, the exterior
windows and window systems, the elevators, the base building mechanical and
plumbing systems including building heating, cooling and ventilation systems
(but not any supplementary systems serving less than the entire Building), major
ventilation distribution ducts to each floor of the Building and the electrical
system from the external power supply source to the electrical panel on each
floor, and life safety systems outside the Demised Premises.

     Landlord at its cost and expense, shall keep and maintain the Building, and
its fixtures, appurtenances, systems and facilities (including the Building
parking garage), and the sidewalks, plazas and landscaped areas located in or
about the Building in good working order, condition and repair and shall make
all repairs as needed in or about the Building, except those repairs for which
Tenant is responsible pursuant to the provisions of Paragraph 8 hereof or which
do not preclude Tenant's reasonable use and enjoyment of the Demised Premises
and the Building.  Landlord shall provide a Building security system comparable
to other first-class office buildings in the downtown Washington, D.C. area and
comparable to what presently exists at the Building as of the date hereof.



The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       14
<PAGE>

10.  ASSIGNMENT AND SUBLETTING
     -------------------------

     (A.)  Restrictions on Tenant.
           ----------------------

          (i) Subject to Subparagraphs (B.) or (C.) below of this Paragraph as
applicable, Tenant shall not, without first obtaining in writing the prior
consent of Landlord, which consent shall not be unreasonably withheld,
conditioned or delayed:  (a) assign, mortgage, pledge, encumber or otherwise
transfer this Lease, the term and estate hereby granted or any interest
hereunder; (b) permit the Demised Premises or any part hereof to be utilized by
anyone other than Tenant for desk space, mailing privileges, or as a concession;
(c) sublet or offer or advertise for subletting the Demised Premises or any part
thereof; or (d) permit any person to occupy the Demised Premises or any part
thereof, other than employees or affiliates of Tenant or clients of Tenant where
such clients, affiliates or employees occupy the space for a temporary period
not to exceed one hundred eighty (180) days and where such occupancy is without
charge by Tenant to such clients, affiliates or employees.

          (ii) Within 10 business days after Landlord's receipt of the
Subletting Notice (as hereinafter defined) or the Assignment Notice (as
hereinafter defined), Landlord shall by notice to Tenant grant or deny its
consent to such request.

          (iii)  If Landlord shall fail to notify Tenant within the 10 business-
day period of Landlord's approval or rejection of Tenant's request to sublet or
assign, Tenant shall give Landlord a notice so advising Landlord (the "Reminder
Notice") together with a duplicate of Tenant's sublet or assignment request.
The first page of such Reminder Notice must contain the following in capitalized
and boldface type:

     LANDLORD'S FAILURE TO APPROVE OR DISAPPROVE THE ATTACHED REQUEST WITHIN TEN
     (10) BUSINESS DAYS AFTER RECEIPT OF THIS NOTICE SHALL BE DEEMED TO BE
     LANDLORD'S APPROVAL OF SUCH REQUEST.

If within ten (10)  business days after Landlord's receipt of the Reminder
Notice, Landlord shall again fail to notify Tenant of Landlord's approval or
disapproval of Tenant's sublet or assignment request, Landlord shall be deemed
to have approved such proposed sublet or assignment.

          (iv) The consent of Landlord to any assignment or other transfer of
this Lease and the term and estate hereby granted or to any subletting or
occupancy may not be unreasonably withheld, conditioned or delayed by Landlord.
Without limiting the other instances in which it may be reasonable for Landlord
to withhold its consent to an assignment (or transfer), or subletting (or
occupancy), Landlord and Tenant acknowledge that it will be reasonable for
Landlord to withhold its consent in any of the following instances:  (a) in
Landlord's reasonable judgment, the financial worth of the proposed assignee or
sublessee does not meet the credit standards applied by Landlord for other
tenants under leases in the Building with comparable terms; (b) in Landlord's
reasonable judgment, the character or reputation of the proposed use of the
Demised Premises by the proposed assignee or sublessee is inconsistent with the
quality of other tenants in the Building; (c) Landlord has received from any
prior lessor to the proposed assignee or subtenant a negative report concerning
such prior lessor's experience with the proposed assignee or sublessee; (d)
Landlord has experienced previous defaults by or is in litigation with the
proposed assignee or sublessee; (e) the proposed assignee or subtenant is a
tenant in the Building and Landlord has space in the Building available for
leasing to such proposed assignee or subtenant; (f) the proposed assignee or
sublessee is a person or entity with whom Landlord is negotiating to lease space
in the Building or whom has asked the Landlord for


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June 23, 1998 Final

                                       15
<PAGE>

a proposal to lease space in the Building; or (g) Tenant is in default of any
obligation(s) of Tenant under this Lease, or Tenant has defaulted under this
Lease on three (3) or more occasions during the previous twelve (12) months
preceding the date that Tenant makes its request for consent.

          (v) Landlord's consent if given shall not relieve Tenant of the
obligation to obtain such consent to any further or subsequent assignment (or
other transfer), or subletting (or occupancy) not expressly permitted under this
Paragraph.  Furthermore, Landlord's consent to any assignment, transfer,
subletting or occupancy shall not be construed as a waiver, discharge, or
release of Tenant, and any immediate or remote successors in interest to Tenant
from liability for the performance or observance of any covenant or obligation
to be performed by Tenant under this Lease even where (a) an agreement has been
undertaken to modify any right or obligation of any party under this Lease, (b)
a stipulation extending the time for performance has been granted by Landlord
from time to time, (c) a waiver of performance has been granted by Landlord from
time to time, or (d) Landlord has failed to enforce any obligation set forth in
this Lease.  The collection or acceptance of rent from any assignee, sublessee
or occupant shall not constitute a waiver or release of Tenant, and any
immediate or remote successors in interest to Tenant from any of its liabilities
or obligations under this Lease.

          (vi) Notwithstanding any other provision of this Paragraph of the
Lease to the contrary, but provided Tenant is not then in default of any
provision of this Lease (regardless of whether any applicable notice has been
given or period to cure expired), Tenant shall have the right to assign this
Lease or sublet the Demised Premises in whole or in part to any Subsidiary or
Affiliate or successor of Tenant, or to any successor partnership, limited
liability company or corporation to Tenant upon giving Landlord not less than
ten (10) business days prior written notice of such assignment or subletting.
Such an assignment or subletting shall not trigger any Landlord right to
terminate the Lease or subsequently require Landlord's consent to any assignee
or sublessee.  A "Subsidiary" of Tenant shall mean any corporation or other
entity not less than fifty percent (50%) of whose outstanding voting stock or a
controlling interest in which shall, at the time, be owned, directly or
indirectly, by Tenant.  An "Affiliate" of Tenant shall mean any corporation or
other entity which, directly or indirectly, controls or is controlled by or is
under common control with Tenant.  For purpose of the definition of "Affiliate,"
the word "control" (including "controlled by" and "under common control with"),
as used with respect to any corporation, partnership, limited liability company
or association, shall mean the possession, directly or indirectly, of the power
to direct or cause the direction of the management and policy of a particular
corporation, partnership, limited liability company or association, whether
through the ownership of voting securities or by contract or otherwise.  A
"successor partnership, limited liability company or corporation" shall mean any
partnership, limited liability company or corporation  (i) into which Tenant is
merged or with which Tenant is consolidated, (ii) to which all or substantially
all of Tenant's business assets or stock shares are transferred, (iii) which has
financial strength commensurate with the obligations of this Lease, and which
(iv) is duly qualified to do business in the District of Columbia.  Tenant shall
promptly furnish to Landlord such information as Landlord may reasonably request
in order to make its determination regarding the financial strength of such
partnership, limited liability company or corporation.

     (vii)    Notwithstanding any other provision of this Paragraph 10 of the
Lease to the contrary, but provided Tenant is not then in default of any
provision of this Lease (regardless of whether any applicable notice has been
given or cure period expired), the following actions shall not constitute an
assignment of this Lease and shall therefore not trigger any right of Landlord
to terminate the Lease pursuant to Paragraph 10 or require Landlord's consent:

     (A)  the transfer or sale of Tenant's stock to employees of Tenant;


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June 23, 1998 Final

                                       16
<PAGE>

     (B)  the sale of any or all of the stock of Tenant to any public company;

     (C)  the sale of Tenant's stock in connection with any public offering by
Tenant; or

     (D) the sale or transfer of stock of Tenant which does not affect control
of the Tenant.

Tenant shall give Landlord notice of any proposed public offering of Tenant's
stock or the sale of substantially all of the stock of Tenant to its employees
or the sale of any or all of the stock of Tenant to any public company.

     (B.)  Proposed Assignments.
           --------------------

     Except as noted in Subparagraph (A.)(vi) and (vii) of this paragraph, in
the event Tenant desires to assign or transfer this Lease then the following
additional provisions shall apply.

          (i) In the event Tenant desires to assign or transfer this Lease, then
at least thirty (30) days, but not more than ninety (90) days prior to the date
that Tenant desires the assignment to become effective (the "Assignment Date"),
Tenant shall give Landlord a written notice (the "Assignment Notice") which
shall set forth the name, address, proposed use, financial information,
including bank references and business of the proposed assignee, the Assignment
Date and the consideration and all other material terms and conditions of the
proposed assignment, all in such detail as Landlord shall reasonably require.

          (ii) If Landlord requests additional detail, the Assignment Notice
shall not be deemed to have been received until Landlord receives such
additional detail.  Landlord shall have the option, exercisable by giving notice
to Tenant at any time within thirty (30) days after Landlord's receipt of the
Assignment Notice, to terminate this Lease as of the date specified in the
Assignment Notice as the Assignment Date.  If Landlord exercises such option,
this Lease, and the term and estate hereby granted, shall terminate as of the
Assignment Date.  No failure of Landlord to exercise such option to terminate
this Lease shall be deemed to be Landlord's consent to the proposed assignment.

          (iii)  If Tenant is a partnership, a limited liability partnership, or
a limited liability company, any dissolution of Tenant or withdrawal or change,
whether voluntary, involuntary or by operation of law, of any general or limited
partner or partners, or alternatively, member or members, of Tenant shall be
deemed a voluntary assignment of this Lease and thus shall be subject to the
provisions of this Paragraph.  If Tenant is a corporation, any dissolution,
merger, consolidation or other reorganization of Tenant, or the sale or transfer
of any stock or any interest in the capital stock of Tenant, voluntarily,
involuntarily or by operation of law, shall be deemed a voluntary assignment of
this Lease and subject to the provisions of this Paragraph.  In the event of any
conflict between the provisions of this Paragraph 10 (B.) (iii) and either
Paragraph 10 A.(vi) or Paragraph 10 (A)(vii), the latter shall govern.

          (iv) In the event that the proposed assignee has a credit rating by
Moody's or Standard and Poor's of AA or better, then provided that  Landlord
consents to such assignment, Tenant shall be relieved of any further obligations
hereunder as of the effective date of the assignment, except that Tenant's
Security Deposit shall not be returned and shall be available to Landlord in
accordance with the provisions of this Lease unless the assignee has provided to
Landlord a replacement Security Deposit in form and substance satisfactory to
Landlord.



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                                       17
<PAGE>

     (C.)  Proposed Sublettings.
           --------------------

     Except as noted in Subparagraph (A.)(vi) of this Paragraph, the following
additional provisions shall apply in the event Tenant desires to sublet the
Demised Premises or permit occupancy thereof by others, in whole or in part.

          (i) Where Tenant desires to sublet the Demised Premises or any part
thereof, or permit the occupancy thereof, then at least thirty  (30) days, but
not more than ninety (90) days, prior to the date when Tenant desires the
subletting to be effective (the "Subletting Date"), Tenant shall give Landlord a
written notice (the "Subletting Notice") which shall set forth the name, address
and business of the proposed sublessee, a detailed description of the space
proposed to be sublet, which must be one or more commercially leasable  self-
contained unit(s) which meet all requirements of the local building, fire and
safety codes (the "Sublet Space"), any rights of the proposed subtenant to use
Tenant's improvements and the like; the Subletting Date and the fixed rent and
other consideration and all other material terms and conditions of the proposed
subletting, all in such detail as Landlord shall reasonably require and which
Subletting Notice shall be accompanied by financial information from the
proposed subtenant for the immediately preceding three (3) calendar years.   If
Landlord requests additional detail, the Subletting Notice shall not be deemed
to have been received until Landlord receives such additional detail.

          (ii) Landlord shall have the option, exercisable by giving notice to
Tenant at any time within thirty (30) days after Landlord's receipt of the
Subletting Notice, to sublease from Tenant all or such part of the Sublet Space
as may be specified in the notice exercising the option (the "Recapture Space")
upon the terms and conditions set forth in the Subletting Notice, except that
the rental rate shall be the lower of a rental rate per square foot derived from
the per square foot Basic Annual Rent (a) specified in the Paragraph of this
Lease entitled "RENT/BASIC ANNUAL RENT" as adjusted pursuant to this Lease and
                ----------------------                                       
that part of the Adjustment Rent described in the Paragraph of this Lease
entitled "OPERATING EXPENSE INCREASES AND REAL ESTATE TAX ADJUSTMENTS" payable
          -----------------------------------------------------------        
under this Lease for the Recapture Space, or (b) a rental rate derived from the
per square foot Basic Annual Rent and other consideration set forth in the
Subletting Notice which is applicable to the Recapture Space and except that
Landlord shall not have the right to sublet the first 10,000 square feet of the
Demised Premises which Tenant desires to sublease.  As to such first 10,000
square feet of the Demised Premises which Tenant desires to sublease, no such
sublease shall be permitted unless and until the proposed subtenant otherwise
meets the requirements of this Paragraph 10.

          (iii)  If Landlord exercises its option to sublet the Recapture Space,
Tenant shall sublet the Recapture Space to Landlord upon the aforesaid terms and
conditions; provided, however, that (a) Landlord shall at all times under such
sublease have the right and option further to sublet the Recapture Space without
obtaining Tenant's consent, (b) the provisions of the Paragraph of this Lease
entitled "USE" and of this Paragraph shall not be applicable thereto as regards
          ---                                                                 
Landlord as sublessee, (c) Landlord and its under subtenants shall have the
right to the use in common with Tenant all lavatories, corridors and lobbies (if
any) which are within the Demised Premises and the use of which is reasonably
required for the use and enjoyment of the Recapture Space, and (d) Landlord's
liability under such sublease shall not, unless expressly assumed or taken
subject to, be deemed assumed or taken subject to by any successor to Landlord's
interest under this Lease (including the holder of any underlying mortgage).  No
failure of Landlord to exercise such option with respect to all of the Sublet
Space shall be deemed to be Landlord's consent to the subletting of all of the
Sublet Space or such portion thereof which does not constitute Recapture Space.


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                                       18
<PAGE>

     (D.)  General Conditions.
           ------------------

          (i) For any period during which Tenant is in default hereunder, Tenant
hereby assigns to Landlord any monies otherwise due to Tenant from any assignee,
transferee, sublessee or occupant of Tenant and hereby authorizes each such
assignee, transferee, sublessee or occupant to make such payments directly to
Landlord to be applied toward the payment of rent by Tenant under this Lease.

          (ii) If the rent paid to Tenant on any subletting, assignment or
occupancy exceeds the rent payable by Tenant to Landlord hereunder (and if the
area of the Demised Premises subleased does not constitute the entire Demised
Premises, the existence of such excess shall be determined on a pro rata basis),
fifty percent (50%) of all such excess shall be paid to Landlord as Additional
Rent hereunder (after reimbursement to Tenant of reasonable costs incurred by
Tenant in connection with such subleasing or assignment).

          (iii)  Tenant may not mortgage or encumber this Lease, without the
prior written consent of Landlord, which consent may be withheld for any reason.

          (iv) Notwithstanding any other provision of this Lease to the
contrary, Tenant shall have no right to transfer, assign, sublet, enter into
license or concession agreements, or mortgage or hypothecate this Lease or
Tenant's interest in the Demised Premises or any part thereof to a foreign
government or to any individual or entity whereby enforcement of the obligations
of the Tenant under this Lease might be limited by sovereign immunity.  Any such
attempted transfer, assignment, subletting, license or concession agreement,
mortgage or hypothecation shall be void and confer no rights on such foreign
government or individual or entity.

          (v) Tenant agrees to pay to Landlord as Additional Rent hereunder the
costs (including reasonable attorneys' fees) incurred by Landlord in connection
with any request by Tenant to obtain Landlord's consent to any assignment,
transfer, mortgage, encumbrance, subletting, or occupancy by Tenant, such
payment by Tenant not to exceed $1,500.00.  Any sublease, occupancy agreement,
assignment or other transfer shall, at Landlord's option, be effected on forms
reasonably approved by Landlord.


11.  ALTERATIONS
     -----------

     (A.) No Alterations without Landlord's Consent.  Without the prior written
          -----------------------------------------                           
consent of Landlord in each instance, which consent shall not be unreasonably
withheld, conditioned or delayed, Tenant will not make, from and after the Lease
Commencement Date or the Mandatory Lease Expansion Commencement Date, as
applicable, any removals, demolition, alterations, improvements, installations,
changes, replacements, additions, or improvements (structural or otherwise,
including without limitation wall paper and coverings, floor tile, ceiling light
fixtures, window blinds and wall to wall carpeting) in or to the Demised
Premises or any part thereof, including work to be undertaken by Tenant related
to its use and occupancy of the Demised Premises (collectively "Alterations"),
including any Alterations relating to any subletting of any portion of the
Demised Premises.  Landlord's consent to any requested Alterations may not be
unreasonably withheld, delayed or conditioned, provided that Tenant has
delivered to Landlord the submissions provided for in Subparagraph (B.) below of
this Paragraph.  Notwithstanding the foregoing, Landlord may withhold its
consent for any reason with regard to the requested Alterations where Landlord
determines in good faith that the Alterations will likely (i) adversely affect
the structure or safety of the Building or the mechanical, plumbing, electrical
or HVAC systems of the


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                                       19
<PAGE>

Building, (ii) are or become visible from the exterior of the Building or any of
the common areas of the Building, (iii) interfere with the operation of the
Building or the provision of services or utilities to other tenants of the
Building, or (iv) could cause Landlord to have to undertake capital improvements
or impose upon Landlord costs which could not be included in Operating Expenses
of the Building. Landlord shall be entitled to at least ten (10) business days
to review Tenant's submissions, but shall timely apprise Tenant of any omissions
or need for additional information as and when discovered by Landlord.
Landlord's consent to a subletting pursuant to the Paragraph of this Lease
entitled "ASSIGNMENT AND SUBLETTING" shall not mean Landlord's consent or
          -------------------------
approval to any related Alterations.

     (B.) Tenant Submissions.  At the time that Tenant makes its request to
          ------------------                                              
Landlord, Tenant, at its sole cost and expense, shall provide Landlord with a
copy of the original or revised full-floor mechanical and electrical plans for
the floor or floors on which the Alterations are to be made, revised by the
Tenant's architect and engineers to show Tenant's proposed Alterations, and a
complete set of any and all architectural and engineering plans for the
Alterations (including, without limitation, structural engineering plans) for
Landlord's review and comment, such review and comment to be completed by
Landlord not later than ten (10) business days after delivery of a complete set
of any and all architectural and engineering plans for the Alterations and such
review and comment to be done using Landlord's reasonable discretion.  Tenant
shall also deliver to Landlord a fee not to exceed Five Hundred Dollars
($500.00) for Landlord's out-of-pocket expenses incurred in connection with a
review of the plans for Tenant's proposed Alterations, provided, however, that
if Tenant has used Landlord's mechanical, electrical and plumbing engineer for
the Building (the "MEP Engineer") to design the plans for Alterations, then such
Five Hundred Dollar ($500.00) processing charge shall be waived by Landlord, and
provided further that Tenant shall use Landlord's designated structural engineer
for the Building for  Tenant's Alterations provided such designated structural
engineer is available to Tenant at a cost not to exceed market rates for such
structural engineering services. Notwithstanding the foregoing, architectural
and engineering plans will not be required for Alterations which do not require
Landlord's prior written consent.

     (C.) Landlord's Oversight and Review of Alterations.  Landlord shall be
          ----------------------------------------------                   
entitled to review the construction, installation and fabrication of Alterations
from time to time as Alterations are being undertaken, but shall not exercise
any direct responsibility over any contractor of Tenant.  Landlord agrees to
promptly bring to Tenant's attention any violation or irregularity observed by
Landlord during the construction, installation or fabrication of any elements of
Alterations.

     (D.) Cost/Approval of Contractors.  All Alterations made or to be made by
          ----------------------------                                       
or on behalf of Tenant shall be undertaken (i) at Tenant's sole expense, (ii) at
such times, in such manner, and pursuant to such rules and regulations as
Landlord may designate, (iii) in a good, workmanlike, first class and prompt
manner, (iv) using new materials only, (v) in accordance with all applicable
legal requirements and the requirements of any insurance company insuring the
Building, as supplied by Landlord, (vi) in accordance with Landlord's
construction rules, if any, as supplied by Landlord, (vii) in satisfaction of
all applicable insurance requirements, at law and under this Lease and (viii)
only in accordance with all applicable governmental codes and regulatory
requirements.  Tenant shall be solely responsible for and shall obtain any
necessary permits from appropriate governmental authorities prior to commencing
work, and shall furnish copies of the permits to Landlord prior to commencement
of any Alterations.  Tenant shall be solely responsible for and shall obtain all
certificates of occupancy required by applicable regulations of the District of
Columbia in order to permit Tenant to occupy and use the altered Demised
Premises.  Tenant shall be solely responsible for all penalties and claims
arising from civil infractions noted by the District of Columbia related to
performance of Alterations or its use and occupancy of the


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                                       20
<PAGE>

Demised Premises. To the extent Landlord incurs costs arising from Tenant's
activities related to construction, installation and/or fabrication of
Alterations arising from damage to the Building or to other areas of the
Building occupied by other tenants, or is required to provide additional
services, such as but not limited to extra security measures, additional
disposal or waste collection services and char and cleaning services, arising
from the ongoing constructions, installations and/or fabrications of
Alterations, Tenant shall reimburse Landlord for such costs (without mark up to
Landlord) within thirty (30) days of receipt by Tenant of a request from
Landlord for reimbursement. Such costs incurred by Landlord shall be deemed
Additional Rent.

     (E.)    Approval of Contractors.  Any and all Alterations shall be made
             -----------------------                                       
only by such contractors, mechanics or suppliers as are approved in writing in
advance by Landlord.  Approval of contractors, suppliers, or mechanics by
Landlord, which approval may not be unreasonably withheld, conditioned or
delayed, shall be based upon the contractors, supplier  or mechanics being
properly licensed, their financial posture, experience and past job performance.
Any contractor employed shall be solely the contractor of Tenant and shall have
no privity or relationship with Landlord.  Tenant shall indemnify Landlord with
regard to all activities of any contractor, mechanic or supplier employed by
Tenant or through any such party employed by Tenant.

     (F.) Alterations Without Landlord's Approval.  If any Alterations are made
          ---------------------------------------                             
without the prior written consent of Landlord, Landlord may correct or remove
the same, and Tenant shall be liable to Landlord for any and all expenses
incurred by Landlord in the performance of this work, including an overhead and
administrative charge equal to fifteen percent (15%) of such expenses incurred
by Landlord, all of which amounts shall be deemed Additional Rent.  Landlord's
prior written consent shall not be required for Alterations consisting of
recarpeting or  repainting of the Demised Premises or the hanging of pictures on
the walls of the Demised Premises where the same are not visible from the common
areas of the Building.

     (G.)  Ownership of Alterations.
           ------------------------

          (i) It is distinctly understood that all Alterations whether made by
or at the expense of Landlord or by Tenant, and including without limitation
wall paper and coverings, floor tile, ceiling light fixtures, window blinds,
wall to wall carpet, and any other fixtures and equipment attached to, or built
into, the Demised Premises as of the Lease Commencement Date or the Mandatory
Expansion Space Lease Commencement Date, as applicable, or during the term of
this Lease (whether made with or without Landlord's consent, and whether or not
made at Landlord's or Tenant's expense) shall be and remain part of the Demised
Premises and be deemed the property of Landlord, to be surrendered with the
Demised Premises at the expiration of this Lease without disturbance,
molestation or injury.

          (ii) Notwithstanding the foregoing Landlord at its option and
discretion may require that Tenant, at Tenant's expense, to remove at the
expiration or any termination of this Lease any or all Alterations to the
Demised Premises made by Tenant, other than the initial improvements to the
Demised Premises made by Tenant on or prior to the date of initial occupancy of
each portion of the Demised Premises, which are unusual in nature and of which
Tenant has been notified by Landlord or Landlord's agent that removal will be
required at the time of installation of the same.  If Tenant is required to
remove any or all Alterations, then Tenant shall repair any damage to the
Demised Premises or Building caused by such removal.  Tenant specifically agrees
to promptly comply with such directions to remove and repair.

          (iii)  In addition to all legal, equitable and other rights and
remedies available to Landlord, it is agreed that if Tenant does not comply with
its obligations under this Paragraph and


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June 23, 1998 Final

                                       21
<PAGE>

such non-compliance continues for a period of ten (10) days after notice to
Tenant (except in the case of an emergency, for which no notice or cure period
shall be required or permitted), Landlord shall have the right (but not the
obligation) to perform or cause to be performed Tenant's obligations, duties and
covenants, in which event Tenant shall reimburse to Landlord within five (5)
days after demand all costs incurred by Landlord to undertake the removal and
repairs, plus a sum equal to fifteen percent (15%) of such costs representing
overhead and administrative expenses of Landlord in such matters, all of which
amounts shall be deemed Additional Rent.


12.  MECHANICS' LIENS AND SIMILAR LIENS
     ----------------------------------

     (A.) Liens Prohibited.  Tenant shall not do or suffer anything to be done
          ----------------                                                   
whereby the Land and/or Building may be encumbered by any mechanic's or
materialmen's lien.  If any mechanic's lien or similar lien is filed against the
Demised Premises, or the Building, for work, labor, services, or materials, done
for or supplied to or claimed to have been done or supplied to Tenant, including
but not limited to Alterations, that lien shall be discharged or bonded off by
Tenant to Landlord's sole satisfaction, at Tenant's sole cost and expense,
within thirty (30) days after the earlier of (i) the date Tenant is delivered
written demand from Landlord to discharge said lien, or (ii) the date Tenant
becomes aware of the filing of such lien (or notice thereof) with the District
of Columbia under applicable law.  If Tenant fails to discharge or
satisfactorily bond off any lien, Landlord may, at its option, discharge the
same and treat the cost thereof as Additional Rent, due and payable upon receipt
by Tenant of a written statement of costs from Landlord.  It is hereby expressly
covenanted and agreed that such discharge or satisfactorily bonding off of any
lien by Landlord shall not be deemed to waive or release Tenant from its default
under the Lease for failing to discharge the same.

     (B.) No Assumption of Liability.  Notice is hereby given that Landlord
          --------------------------                                      
shall not be liable for any labor or materials furnished or to be furnished to
Tenant upon credit, and that no mechanic's or materialmen's or other lien for
any such labor or materials shall attach to or affect the reversionary or other
estate or interest of Landlord in and to the Land and Building.  In no event
shall Landlord be deemed to be the agent of Tenant for purposes of Title 38-101
of the District of Columbia Code (1981 Edition, as amended) and no contractor of
Tenant shall by virtue of its contract be entitled to assert any mechanic's lien
against the Building or land appurtenant thereto.

     (C.) Indemnification.  Tenant will indemnify and hold harmless Landlord
          ---------------                                                  
from and against any and all claims, damages and expenses incurred by Landlord,
arising from any liens placed against the Demised Premises or the Building and
the Land as a result of Tenant undertaking Alterations or other work.


13.  PERSONAL PROPERTY
     -----------------

     (A.) No Liability of Landlord.  Tenant's personal property, including but
          ------------------------                                           
not limited to its furniture, fixtures and equipment, and the property of any
officer, employee and invitee, and of any agent, contractor, subtenant or
occupant brought into and located within the Building or within the Demised
Premises shall remain therein as the sole risk of such party.  Landlord shall
have no liability for any accident to or damage to such personal property and
obligation to protect, repair or restore the same.  Landlord shall not, in any
event, be liable for damages to any property of Tenant or any other party,
resulting from water, steam or other causes.  Tenant hereby expressly releases
Landlord from any liability for damages.



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June 23, 1998 Final

                                       22
<PAGE>

     (B.) Removal Upon Expiration or Earlier Termination of Lease.
          -------------------------------------------------------

          (i) Tenant shall remove all of its personal property not affixed or
attached to the Demised Premises from the Building and the Land at the
expiration or earlier termination of the Lease.  As provided in Paragraph 11 of
this Lease entitled "ALTERATIONS", any property identified as an Alteration but
                     -----------                                              
which may be removed without causing material damage to the Demised Premises and
which was installed by and at the sole expense of Tenant ("Tenant's Property")
shall be deemed to be the personal property of Tenant and, unless Tenant is in
default under this Lease, may be removed from the Demised Premises by Tenant
upon notice to Landlord prior to the expiration of the term of this Lease or
before any earlier termination thereof.  Tenant shall be obligated however to
repair any damage to and restore the Demised Premises and/or the Building
occasioned by such removal to a condition no less than Building standard
condition specified in Exhibit D attached hereto and made a part thereof, or
                       ---------                                           
shall reimburse Landlord immediately upon demand for the cost of repairing such
damage if Tenant fails to timely repair, which costs incurred by Landlord shall
become Additional Rent under this Lease.  Tenant shall schedule its move-out of
the Demised Premises with Landlord in advance and Landlord will make the freight
elevator available to Tenant for Tenant's move-out in the exercise of Landlord's
reasonable discretion.

          (ii) In the event Tenant fails to remove any of its personal property,
including Tenant's Property, which Tenant was obligated to remove, such property
shall be deemed abandoned by Tenant and Landlord may remove that property from
the Demised Premises at Tenant's expense.  Tenant hereby agrees to pay to
Landlord, as Additional Rent, the cost of this removal together with any and all
damages which Landlord may suffer and sustain by reason of the failure of Tenant
to remove the same.  This amount of Additional Rent shall be due and payable
upon receipt by Tenant of a written statement of costs and damages from
Landlord.

          (iii)  If Tenant is in default under this Lease, then notwithstanding
the provisions of Subparagraph (B.)(i.) of this Paragraph, it shall not remove
any of its personal property, including Tenant's Property, without Landlord's
prior written consent.


14.  DELIVERIES AND MOVING OF PROPERTY BELONGING TO TENANT.
     -----------------------------------------------------

     (A.) Delivery and Moving to, from or within Building.  No furniture,
          -----------------------------------------------               
equipment or other bulky matter of any description (including but not limited to
materials related to construction, installation and/or fabrication of
Alterations) shall be received into or removed from the Building, moved through
the common area of the Building or carried in the elevators of the Building,
except in the manner and during the times reasonably approved by Landlord and in
accordance with any policies and procedures of Landlord in effect from time to
time.  Tenant shall obtain Landlord's prior determination as to the manner and
the time that delivery, and/or movement into, out of or through the Building is
permitted prior to moving said property into, out of or through  the Building.

     (B.) Supervision of Deliveries and Moving.  All moving of furniture,
          ------------------------------------                          
equipment and such other items noted in Subparagraph (A.) of this Paragraph
within the public areas shall be coordinated with Landlord, who shall, however,
not be responsible for any damage resulting from, to or charges for moving the
same.

     (C.) Elevator Load Capacities.  Landlord shall have the sole right to
          ------------------------                                       
determine the load capacities of the elevators of the Building and to determine
the furniture, equipment and other such


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June 23, 1998 Final

                                       23
<PAGE>

items noted in Subparagraphs (A.) of this Paragraph if can be safely transported
in the elevators.

     (D.) Clearing Property from Public Spaces.  Tenant agrees promptly to
          ------------------------------------                           
remove from the sidewalks adjacent to the Building any of the property of Tenant
or any other person or entity claiming rights under this Lease by and through
Tenant, including but not limited to furniture, equipment or other materials
delivered or deposited there.

     (E.) Responsibility for Damage. Subject to the provisions of Paragraph
          -------------------------                                       
22(C)(iii), all damage done to the Demised Premises and to the Building by the
taking in or removal of any property of Tenant referred to in this Paragraph
(including but not limited to materials related to construction, installations
or fabrication of Alterations), or due to its being in the Demised Premises,
shall be repaired at the expense of Tenant.  Tenant hereby agrees to pay
Landlord, as Additional Rent, the cost of any repairs of such damage not
undertaken by Tenant.  The amount of Additional Rent shall be due and payable by
Tenant upon receipt by Tenant of a written statement of costs from Landlord.

15.  TENANT'S EQUIPMENT
     ------------------

     (A.) No Equipment without Consent.  Without first obtaining Landlord's
          ----------------------------                                    
prior written consent, which consent shall not be unreasonably withheld or
delayed, but which may be reasonably conditioned, Tenant shall not install or
operate in the Demised Premises any electrically operated equipment or other
machinery, other than typewriters, word processing machines, desktop personal
computers, adding machines, postage meters, radios, televisions, tape recorders,
dictaphones, telecopiers, bookkeeping machines, copying machines, clocks, and
other business machines and equipment normally employed for general office use
in first-class office buildings and which do not require high electricity
consumption for operation or do not require dedicated circuitry.  Furthermore
Tenant shall not install any equipment of any kind or nature whatsoever that
will or may necessitate any changes, replacements or additions to, the water
system, plumbing system, heating system, or air conditioning system of the
Demised Premises or of the Building without the prior written consent of
Landlord, which consent shall not be unreasonably withheld or delayed, but which
may be reasonably conditioned.

     Landlord may condition its consent to installation and operation of
equipment upon the agreement of Tenant to pay to Landlord, as Additional Rent,
compensation for additional consumption of electricity and/or other utility
services, including but not limited to, water for cooling purposes.  Such
consumption charges shall be in addition to Tenant's obligations, pursuant to
the Paragraph of this Lease entitled "OPERATING EXPENSE INCREASES AND REAL
                                      ------------------------------------
ESTATE TAX ADJUSTMENTS" to pay its proportionate share of increases in Operating
----------------------                                                         
Expenses.

     If Tenant's equipment causes Tenant's consumption of electricity for lights
and power to exceed an average of five (5) watts per rentable square foot or
causes other utility service consumption above Building standard levels, or if
such equipment is to be consistently operated beyond the normal Building hours
of 8:00 a.m. to 7:00 p.m., Monday through Friday, and 9:00 a.m. to 1:00 p.m. on
Saturday, exclusive of designated holidays, ("Building Standard Hours"),
Landlord may install at its option and as applicable (i) a separate electric
meter for the Demised Premises at Tenant's sole cost and expense, (ii) a
separate electric meter for the specific equipment that is causing Tenant's
excessive consumption of electricity, and/or (iii) other separate monitoring
devices to measure utility consumption, all at Tenant's sole cost and expense.
In the event Landlord installs any separate meter for the Demised Premises,
Tenant shall then pay the cost of consumption as recorded by such meter directly
to the utility company to the extent such


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       24
<PAGE>

consumption exceeds the level specified above in this paragraph. In the event
that separate billing by the utility service provider is not possible, Landlord
will separately monitor consumption and bill Tenant periodically based upon such
excess consumption. Any claims for reimbursement and any billing by Landlord to
Tenant under this Subparagraph of the Lease shall be deemed Additional Rent due
and owing by Tenant.

     Furthermore, if any or all of Tenant's equipment exceeds the level
specified above and requires electricity consumption in excess of the capacity
of the electrical system installed by Landlord in the Demised Premises and/or
dedicated circuitry, and/or consumption of other utility services in excess of
the capacity of the Building's systems at the Demised Premises, and/or types of
utility services that are not available in the Building, then if approved by
Landlord, any installation of additional transformers, pumps, distribution
panels, wiring, plumbing or other modifications to the Building's systems or
structure related thereto shall be at Tenant's sole expense, and any expense
incurred by Landlord related thereto shall be treated as Additional Rent due and
payable to Tenant.  Necessary modifications to the Building's systems, utilities
and structure to address these needs of Tenant's equipment approved by Landlord
shall only be undertaken by Landlord, unless Landlord otherwise permits Tenant
to undertake such work.

     (B.) Maintenance and Repair of Equipment.  Maintenance and repair of
          -----------------------------------                           
Tenant's equipment, including but not limited to telecommunications equipment,
office equipment, kitchen fixtures, separate air conditioning equipment, or any
other type of equipment, whether installed by Tenant or by Landlord on behalf of
Tenant, specially related to Tenant's use and occupancy of the Demised Premises,
shall be the sole responsibility of Tenant, and Landlord shall have no
obligation in connection therewith.  Tenant shall maintain such equipment in
good working order and condition, subject to all other applicable provisions of
this Lease.

     (C.) No Modifications of Building Systems.  Tenant shall not install any
          ------------------------------------                              
equipment of any kind or nature whatsoever which will or may necessitate any
changes, replacements or additions to, or in the use of, the water system,
heating system, plumbing system, air-conditioning system, or electrical system
of the Demised Premises or the Building without first obtaining the prior
written consent of Landlord, not to be unreasonably withheld or delayed, but
which may be reasonably conditioned.

     (D.) Noise or Vibration.  Business machines and mechanical equipment
          ------------------                                            
belonging to Tenant which cause noise or vibration that may be transmitted to
the structure of the Building or to any space therein to such a degree as to be
objectionable to Landlord or to any tenant in the Building shall be installed by
Tenant, at Tenant's expense, with vibration eliminators or other devices
sufficient to eliminate such noise and vibration.  Tenant shall maintain such
devices at its sole expense.  Any expense in this regard incurred by Landlord
shall be deemed Additional Rent.

     (E.) Location of Heavy Equipment.  Landlord shall have the right to
          ---------------------------                                  
prescribe the weight and position of all heavy equipment and fixtures,
including, but not limited to, data processing equipment, record and file
systems, and safes which Tenant intends to install or locate within the Demised
Premises.  Tenant will not install in the Demised Premises any fixtures,
equipment or machinery that will place a load upon any floor exceeding the floor
load per square foot area which such floor was designed to carry.  Tenant shall
obtain Landlord's prior review and approval before installing or locating heavy
equipment and fixtures in the Demised Premises.  If installation or location of
such equipment or fixtures, in Landlord's opinion, requires alterations to the
Demised Premises or the Building, Tenant agrees to reimburse Landlord, as
Additional Rent, for any and all costs incurred by Landlord to make such
required modifications or reinforcements, and such modifications or
reinforcements to the Building and Tenant shall make such required modifications
or reinforcements to the interior of the Demised Premises, all of which


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       25
<PAGE>

modifications or reinforcements shall be completed prior to Tenant installing or
locating such equipment or fixtures in the Demised Premises.  Tenant shall
reimburse Landlord within thirty (30) days of receipt of any statement setting
forth those costs.


16.  SIGNS AND ADVERTISEMENTS
     ------------------------

     (A.) No Signs without Consent.  Tenant may not inscribe, paint or affix
          ------------------------                                         
sign, advertisement or notice on any part of the outside of the Demised Premises
or Building or any sign, notice or advertisement inside the Demised Premises
which is visible from the common areas of the Building or the exterior of the
Building, except on the directories and doors of offices, and then only in such
size, color and style as Landlord shall reasonably approve.  Tenant may display
its name on the main entry door(s) of the Demised Premises in Building standard,
color, size and style of lettering, or as Landlord may otherwise approve, at
Tenant's expense.

     (B.) No Advertisements Without Consent.  Landlord may have the right to
          ---------------------------------                                
prohibit any advertisement of Tenant which in Landlord's reasonable opinion
tends to impair the reputation of the Building or its desirability as a Building
for offices or for financial, insurance or other institutions and businesses of
like nature, and upon written notice from Landlord, Tenant shall refrain from
and discontinue such advertisement.

     (C.) Building Directory.  Tenant shall have a proportionate share of
          ------------------                                            
listings in the Building's directory  at the time of Tenant's occupancy of the
Initial Demised Premises (which share shall increase as the Demised Premises
increases) in the size and style of lettering used by Landlord, at Landlord's
expense.  Any changes to such display requested by Tenant shall be done at
Tenant's sole expense.

17.  LANDLORD'S ACCESS
     -----------------

     (A.) Landlord's Right to Access.  Upon reasonable prior notice to Tenant,
          --------------------------                                         
which may be less than one (1) Business Day, Tenant shall permit Landlord, or
its agents, employees or contractors, as well as Landlord's mortgagees to enter
the Demised Premises at all reasonable times and in a reasonable manner, without
charge to Landlord or diminution of rent, including Basic Monthly Rent and
Adjustment Rent, payable by Tenant, to examine, inspect and protect the
Building, and to make any repairs as in the judgment of Landlord may be deemed
necessary to maintain or protect the Building, or to exhibit the Building to
prospective tenants, purchasers and lenders. In the event of any emergency, no
prior notice from Landlord shall be required before Landlord or its agents
enters the Demised Premises. Landlord shall use reasonable efforts to minimize
interference with Tenant's business when making repairs, but Landlord shall not
be required to perform the repairs at a time other than during normal working
hours.  At Tenant's request, a representative of Tenant may accompany Landlord,
provided that such request does not delay Landlord's or Landlord's agents entry
in the event of an emergency.

     (B.) Emergency Access.  In the event of an emergency, Landlord may enter
          ----------------                                                  
the Demised Premises without notice and make whatever repairs are necessary to
protect the Building and the base building systems.

     (C.) Additional Permitted Access.   Upon reasonable prior notice, except in
          ---------------------------                                          
the case of an emergency, Tenant shall permit Landlord, or its agents, employees
or contractors, upon prior notice to Tenant, to enter the Demised Premises at
reasonable times and in a reasonable manner, without charge to Landlord or
diminution of Basic Monthly Rent and Adjustment Rent payable by Tenant, (i) to
make installations related to the construction of pre-occupancy tenant work
being


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       26
<PAGE>

performed by Landlord for other tenants of the Building, (ii) to make repairs,
alterations and improvements arising due to repairs, alterations and
improvements to any areas adjoining the Demised Premises, (iii) to erect, use
and maintain pipes and conduits in and through the Demised Premises, (iv) to
make alterations, installations, improvements and repairs to the Building, or
(v) to make installations, improvements, and repairs to the utility services of
the Building. Landlord shall use reasonable efforts to minimize any interference
with Tenant's business operations, but except in unusual circumstances, Landlord
shall not be required to perform such work at a time other than during Building
Standard Hours.

18.  SERVICES
     --------

     (A.) Building Services to Be Provided.  Landlord shall furnish to Tenant
          --------------------------------                                  
reasonably adequate electric current (not to exceed five (5) watts per square
foot of the Demised Premises for lighting and power), water, lavatory supplies,
Building standard ballasts and fluorescent tube replacements, automatically
operated elevator service and normal and usual cleaning and char service after 7
p.m. and consistent with the specifications set forth in Exhibit F  (Mondays to
                                                         ---------            
Fridays, both inclusive, except on holidays) , all consistent with the standards
of a first-class office building located in downtown Washington, D.C., without
additional cost to Tenant, excepting only Tenant's obligation to pay Basic
Monthly Rent and Additional Rent.  Landlord further agrees to furnish heat and
air conditioning (based upon human occupancy of not more than one (1) person per
each 120 square feet of rentable area) during the appropriate seasons of the
year.  It is also agreed that if Tenant desires air-conditioning, heat, or other
Building standard services beyond the Building Standard Hours or on recognized
holidays and provided arrangements are made therefor with Landlord's management
agent (with such reasonable advance written notice of such desire as Landlord or
its management agent may require from time to time), Landlord will make
available such air-conditioning, heat, or other Building services outside of the
Building Standard Hours and on recognized holidays and Tenant agrees to pay for
the same, as Additional Rent, with the next monthly installment of Basic Monthly
Rent or at such other time(s) as Landlord may require, in accordance with the
then current schedule of costs and assessments therefor charged by Landlord. As
of the date of this Lease, the cost charged by Landlord for such after-hours
Building services is $26.00 per hour per (approximately) one half floor.  This
cost is subject to change from time to time, if and to the extent Landlord's
cost therefor increases as determined by Landlord in Landlord's sole, but
reasonable, discretion.   Landlord shall not be liable for failure to furnish,
or for suspension or delays in furnishing, any services required of Landlord
under this Lease, provided however, that in the event there is a failure of
Building services for a period of more than ten (10) consecutive business days,
and (1) such failure of Building services is within Landlord's reasonable
control to remedy, (2) such failure renders all or at least twenty percent (20%)
of the square footage of the Demised Premises untenantable for such ten (10)
consecutive business day period, (3) Tenant in fact does not use that portion of
the Demised Premises rendered untenantable, (4) Tenant is not then in default in
its obligations under the Lease, (5) Tenant's inaction or actions were not the
cause of the failure of Building services, and (6) Tenant has given Landlord
written notice of the failure of Building services and Landlord has not remedied
such failure within the aforesaid ten (10) consecutive business days  period or
such longer period as Landlord determines in good faith is reasonably necessary
to remedy such failure of Building services, provided that Landlord is
diligently pursuing such remedy, then that portion of  Basic Monthly Rent which
corresponds to the portion of the Demised Premises rendered untenantable shall
be abated until such time as the failure of services is corrected.  Landlord
shall use reasonable, good faith efforts to restore such Building services.


     (B.) Conservation Controls.  Tenant agrees on behalf of itself and its
          ---------------------                                           
subtenants to comply with all mandatory and voluntary conservation controls and
requirements applicable to


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       27
<PAGE>

office buildings that are imposed or instituted by the Federal or District of
Columbia governments, including without limitation, controls on the permitted
range of temperature settings in office buildings and requirements necessitating
curtailment of the volume of energy consumption of the hours of operation of the
Building. Any terms or conditions of this Lease that conflict or interfere with
compliance with such controls or requirements shall be suspended for the
duration of such controls or requirements. It is further agreed that compliance
with such controls or requirements shall not be considered an eviction, actual
or constructive, of Tenant from the Demised Premises or a violation of
Landlord's covenants set forth in the Paragraph of this Lease entitled
"COVENANTS OF LANDLORD," and shall not entitle Tenant to terminate this Lease or
 ---------------------
to an abatement of any rent payable hereunder.

     (C) Additional Landlord Services.  Landlord shall manage and operate the
         -----------------------------                                      
Building as a first-class office building in the Washington, D.C. area.
Landlord, at its cost and expense, shall keep and maintain the Building, and its
fixtures, appurtenances, systems and facilities (including the garage) and the
sidewalks, plaza and landscaped areas located thereon in good order, condition
and repair.  Landlord, at its cost and expense, shall: (i) keep the sidewalks,
plazas and landscaped areas adjoining the Building free of accumulations of
snow, ice, dirt, refuse, rubbish and unlawful obstructions; (ii) keep the
Building atrium, lobbies and the common areas of the Building clean; (iii) care
for and maintain the shrubbery, planting and landscaping, if any, on the plaza
or plazas adjacent to the Building or other public areas of the Building; (iv)
provide a Building security system as reasonably determined by Landlord to be
comparable to that of other comparable office buildings in the area; (v) provide
Tenant, its employees and invitees prompt access into the Building, the Demised
Premises, and the Building garage twenty-four (24) hours each day, seven (7)
days per week.

19.  RULES AND REGULATIONS
     ---------------------

     Tenant, its agents, employees and guests shall abide by and observe the
rules and regulations attached hereto as Exhibit C and such other reasonable
                                         ---------                         
rules and regulations as may be promulgated from time to time by Landlord which
in Landlord's judgment are needed for the general well being, safety, care,
operation, maintenance and cleanliness of the Demised Premises and the Building,
provided a copy thereof is sent to Tenant.  Nothing contained in this Lease
shall be construed to impose upon Landlord any duty or obligation to enforce
such rules and regulations, or the terms, conditions or covenants contained in
any other lease as against any other tenant, and Landlord shall not be liable to
Tenant for violation of the same by any other tenant, any other tenant's
employees, agents, business invitees, licensees, customers, clients, family
members or guests.  Landlord shall not discriminate against Tenant in the
enforcement of any rule or regulation however.


20.  DAMAGE BY TENANT
     ----------------

     Subject to the provisions of Paragraph 22 (C)(iii) , Tenant shall be
responsible for all damage or injury to the Demised Premises or the Building
caused by Tenant, or its agents, employees, contractors and invitees doing work
in or about the Building or moving property into, in or out of, the said
Building and all breakage done by Tenant or its agents, employees, contractors
and invitees.  Landlord may make such repairs or undertake appropriate
corrective action on Tenant's behalf, or at Landlord's sole election direct
Tenant to promptly repair or correct the damage under Landlord's supervision.
Any charge or cost incurred by Landlord shall be the sole responsibility of
Tenant due and payable by Tenant as Additional Rent, as and when billed to
Tenant by Landlord.  This provision shall be construed as an additional remedy
granted


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June 23, 1998 Final

                                       28
<PAGE>

to Landlord and not in limitation of any other rights and remedies which
Landlord has or may have in said circumstances.


21.  LIABILITY
     ---------

     (A.) No Landlord Liability.  Landlord assumes no liability or
          ---------------------                                  
responsibility whatsoever with respect to the conduct and operation of the
business to be conducted in the Demised Premises.  Neither Landlord nor its
management agent shall be liable for any accident or injury to any person or
persons or property in or about the Demised Premises which are caused by the
conduct and operation of said business, or by virtue of equipment or property of
Tenant in the Demised Premises and which are not due to Landlord's gross
negligence or willful misconduct or that of Landlord's agents.

     (B.) Indemnification of Landlord. Tenant shall defend and hereby does
          ---------------------------                                    
indemnify and save harmless Landlord and Landlord's officers, directors,
partners, agents and employees (collectively, "Landlord's Indemnitees") from and
against all liability (statutory or otherwise), claims, suits, causes of action,
demands, judgments, costs, interest and expenses (including also reasonable
attorneys' fees and disbursements incurred in the defense thereof) to which any
Landlord's Indemnitees may (except insofar as it arises out of the negligence or
the intentional act or failure to act of such Landlord Indemnitees or their
contractors) be subject or suffer, whether by reason of any claim for, any
injury to, or death of, any person or persons or damage to or loss of property
(including also any loss of use thereof) or otherwise, and arising from or in
connection with the use by Tenant of, or from any work or anything whatsoever
done by Tenant (or any of its officers, directors, agents, contractors,
employees, licensees or invitees) in any part of the Demised Premises or the
Building (other than by Landlord or its agents or contractors) during the term
of this Lease.  Tenant's agreement to indemnify and save harmless shall also
apply during the period of time, if any, prior to the  Lease Commencement Date
and the Mandatory Expansion Space Lease Commencement Date, as applicable, with
respect to such part of the Demised Premises and/or the Building that Tenant may
have been given access to for the purpose of undertaking Alterations, or
preparing to conduct the Alterations or arising from any condition of the
Demised Premises or the Building due to or resulting from any default by Tenant
in the keeping, observance or performance of any covenant or agreement contained
in this Lease or from any fault or neglect of Tenant or any of its officers,
directors, agents, contractors, employees, licenses or invitees.

     (C.)  Indemnification of Tenant.  Landlord shall defend, and hereby does
           --------------------------                                       
indemnify and save harmless Tenant and Tenant's officers, directors, partners,
and employees (collectively, "Tenant Indemnitees") from and against all
liability (statutory or otherwise), claims, suits, causes of action, demands,
judgments, costs, interest and expenses (including also reasonable attorneys'
fees and disbursements incurred in the defense thereof) to which any Tenant
Indemnitees may (except insofar as it arises out of the fault or neglect of such
Tenant Indemnitees or their contractors) be subject or suffer, whether by reason
of any claim for, any injury to, or death of, any person or persons or damage to
or loss of Tenant's Business Property  (which shall mean Tenant's personal
property used in the operations of its business, including, but not limited to,
fixtures, furnishings and equipment) and arising from or in connection with the
negligence or the intentional act or omission of Landlord or its agents,
contractors, and employees in or about any part of the Demised Premises or the
Building during the term of this Lease or any renewal or extension thereof.


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       29
<PAGE>

22.  INSURANCE
     ---------

     (A.)  Insurance Rating
           ----------------

          (i) Tenant hereby covenants and agrees that it will not do or permit
anything to be done in or on the Demised Premises, the Building, or the Land, or
bring or keep anything therein that shall in any way increase the rate of fire
or other insurance on said Building, or on the property kept therein, or
conflict with the fire laws or regulations, or with any insurance policy upon
said Building or any part thereof, or with any statutes, rules or regulations
enacted or established by the appropriate governmental authority.  If any acts
or omissions of Tenant in violation of this Paragraph should cause any increase
in the premiums for any insurance carried by Landlord above standard rates for
the Building occupied for normal office use, then Landlord, in addition to any
other remedies it may have, shall be entitled to immediate reimbursement from
Tenant, as Additional Rent, of all such excess costs for insurance premiums
occasioned by such acts or omissions of Tenant.

          (ii) Nothing contained in this Paragraph, or in any other Paragraph of
this Lease, shall obligate Landlord to enforce the provisions of this Paragraph
for the benefit of any other tenant or occupant of space in the Building.  It is
expressly understood and agreed that all such provisions are included in this
Lease solely for Landlord's benefit and for its enforcement at its exclusive
option and discretion.  Similarly, Tenant shall have no right to require
Landlord to enforce such or similar provisions in other leases for the benefit
of Tenant, any such enforcement being solely in Landlord's discretion.

     (B.) Commercial General Liability Insurance.  Tenant shall obtain and
          --------------------------------------                         
maintain in effect at all times during the term of this Lease, a policy of
commercial general liability insurance, against any liability for bodily injury,
death or property damage occurring upon, in or about any part of the Demised
Premises, the Building or the Land, written on an occurrence basis, and
including contractual liability coverage, premises and operations coverage,
broad form property damage coverage and independent contractors coverage, and
containing an endorsement for personal injury.  Such policies of insurance shall
afford protection with respect to bodily injury or death of not less than Two
Million Dollars ($2,000,000.00) as concerns one person in any one occurrence,
and Four Million Dollars ($4,000,000.00) as concerns more than one person in any
occurrence, and not less than Two Hundred Fifty Thousand Dollars ($250,000.00)
with respect to damage to property, in all cases with commercially reasonable
deductible amounts permitted.  Neither the issuance of any insurance policy
required under this Lease, nor the minimum limits specified herein with respect
to Tenant's insurance coverage, shall be deemed to limit or restrict in any way
Tenant's liability arising under or out of this Lease.  Copies of said policies
and renewals, with evidence of premiums paid, will be delivered to Landlord
promptly on its request.  The provisions of this Paragraph shall not limit in
any fashion the liability of Tenant under the Paragraph of this Lease entitled
"LIABILITY."
---------- 

     (C.)  All Risk Coverage Insurance
           ---------------------------

          (i) Landlord shall obtain and maintain All Risk Coverage insurance
covering the Building and the base building operating systems thereof, in an
amount not less than 80% of Landlord's estimate of replacement cost and in an
amount sufficient to replace the Building and building standard improvements in
the Demised Premises  as specified in Exhibit D attached hereto and made a part
                                      ---------                               
hereof.

          (ii) Tenant shall obtain and maintain throughout the term of this
Lease, including any extension periods All Risk Coverage insurance insuring
against damage to and loss


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       30
<PAGE>

of Alterations above building standard alterations, and the fixtures, equipment,
furniture, and personal property in and about the Demised Premises of Tenant,
its officers, employees, contractors, agents and invitees with deductibles in an
amount reasonably acceptable to Landlord.

          (iii)  Notwithstanding anything to the contrary contained in this
Lease, Landlord and Tenant hereby release each other and waive any claims they
may have against the other for loss or damage to the Building, Demised Premises,
tenant improvements including Alterations, fixtures, equipment and/or any other
personal property arising from a risk insured against under the All Risk
Coverage insurance policies carried or required to be carried by Landlord and
Tenant, as required above, even though such loss or damage was caused by the
negligence of Landlord, Tenant, or their respective agents or employees (or any
combination thereof).  Landlord and Tenant agree to obtain and maintain
throughout the term of this Lease endorsements to their respective All Risk
Coverage policies waiving the right of subrogation of their insurance companies
against the other party and its agents and employees.

     (D.) Worker's Compensation Insurance.  Tenant shall carry and keep in full
          -------------------------------                                     
force and effect at all times during the term of this Lease, at its sole cost,
worker's compensation or similar insurance in form and amounts required by law,
with a commercially reasonable deductible amount.  Such insurance shall contain
waiver of subrogation provisions in favor of Landlord and its agent, if
available.

     (E.) Business Interruption Insurance.  Tenant shall obtain and maintain
          -------------------------------                                  
throughout the term of this Lease business interruption insurance, with
deductibles in an amount reasonably acceptable to Landlord.  Such insurance
shall be in minimum amounts typically carried by prudent tenants engaged in
similar operations to Tenant, but in no event in an amount less than five (5)
times the Basic Annual Rent in effect from time to time.

     (F.) Employer's Liability Insurance.  Tenant shall obtain and maintain
          ------------------------------                                  
throughout the term of this Lease employer's liability insurance.  Such
insurance shall be in an amount not less than One Million Dollars ($1,000,000)
for each accident, One Million Dollars ($1,000,000) disease policy limit and One
Million Dollars ($1,000,000) disease each employee, with no deductible amount
permitted.

     (G.) Tenant's Contractor's Insurance.  Tenant shall require any contractor
          -------------------------------                                     
of Tenant performing work on the Demised Premises to carry and maintain, at no
expense to Landlord:

          (i) commercial general liability insurance, including contractor's
liability coverage, contractual liability coverage, completed operations
coverage, broad form property damage endorsement and contractor's protective
liability coverage, to afford protection with limits, for each occurrence, of
not less than One Million Dollars ($1,000,000.00) with respect to personal
injury, death, property damage with a commercially reasonable deductible amount
permitted; and

          (ii) worker's compensation or similar insurance in form and amounts
required by law.


23.  REQUIREMENTS FOR TENANT'S INSURANCE POLICIES
     --------------------------------------------

     (A.) Requirements.  The company or companies writing any insurance which
          ------------                                                      
Tenant is required to carry and maintain, or cause to be carried or maintained,
pursuant to this Lease, as


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       31
<PAGE>

well as the form of such insurance, shall at all times be subject to Landlord's
reasonable approval and any such company or companies shall be good and
responsible, licensed to do business in the District of Columbia, and have a
rating equal to or exceeding A:XI from Best's Insurance Guide. All commercial
general liability and all risk coverage insurance policies required to be
provided by Tenant and certificates evidencing such insurance shall name
Landlord, its management agent and mortgagee (if any) as additional insureds or
loss payees as applicable. Each policy of insurance shall contain a provision by
which the insurer agrees that such policy may not be canceled, refused for
renewal, reduced in amount of insurance or changed as to coverage (i) if due to
Tenant's action or failure to act, and (ii) without the insurer first giving
Landlord thirty (30) days prior written notice of such action. Tenant agrees to
provide to Landlord prior to taking possession of the Demised Premises the
certificates evidencing such insurance; Landlord may withhold delivery of the
Demised Premises without delaying the Lease Commencement Date or Mandatory
Expansion Space Lease Commencement Date, as applicable, or triggering any
abatement of rent, if Tenant fails to provide Landlord with these certificates.
All deductibility limits applicable to any policy of insurance must be
reasonably acceptable to Landlord.

     (B.) Primacy of Insurance.  Any insurance carried or to be carried by
          --------------------                                           
Tenant hereunder shall be primary over any policy that might be carried by
Landlord.  If Tenant shall fail to perform any of its obligations regarding the
acquisition and maintenance of insurance, Landlord may perform the same and the
cost of same shall be deemed Additional Rent, payable upon Landlord's demand.
Tenant may satisfy any insurance obligation hereunder through blanket or
umbrella coverage, provided that in the event Tenant obtains blanket insurance
policies for liability or property damage coverage, then each such policy shall
have an agreed amount endorsement for the Tenant's activities and the Tenant's
property located at the Demised Premises.


24.  DAMAGE BY FIRE OR OTHER CASUALTY
     --------------------------------

     (A.) Fire or Casualty of the Demised Premises. In the event of damage or
          ----------------------------------------                          
destruction of the Demised Premises by fire or any other casualty, except as
otherwise expressly provided in this Paragraph, this Lease shall not terminate,
but the Demised Premises shall be promptly and fully repaired and restored by
Landlord at its own cost and expense, subject however, to the following terms
and conditions.  Landlord's obligation to repair and restore the Demised
Premises shall be limited and conditioned, at Landlord's option and absolute
discretion, to its receipt and availability of sufficient insurance proceeds to
cover all costs of such repairs and restoration including any related or
attendant work.  Any such repairs and restoration to be performed by Landlord
under this Paragraph shall be limited to building standard levels and condition
as specified in Exhibit D attached hereto.  Landlord shall have no obligation to
                ---------                                                      
restore or replace Alterations in excess of building standard levels and
conditions  specified in Exhibit D, or Tenant's Property, or any of the personal
                         ---------                                             
property of Tenant or others.

     (B.) Termination of Lease.  Landlord reserves the right to elect not to
          --------------------                                             
repair, and instead to terminate this Lease,  if:  (i) damage to the Demised
Premises (but not including Alterations) is so extensive that, in Landlord's
reasonable judgment, such damage cannot be substantially repaired within one
hundred eighty (180) days from the date of the fire or other casualty, all  as
more fully set forth in subparagraph D Mutual Rights to Terminate hereinbelow,
                                       --------------------------            
or (ii) if more than one-half (1/2) of the total rentable area of the Building
is rendered untenantable.  Within thirty (30) days after the occurrence of any
fire or other casualty damage to the Demised Premises, Landlord shall notify
Tenant as to whether or not such damage can be repaired or restored within the
180 day period above-described or whether Landlord will terminate this Lease. In
the case of damage to the Building, Landlord shall notify Tenant within thirty
(30) days after the occurrence of a fire or other casualty affecting the
Building as to whether more than one-half (1/2) of the total


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June 23, 1998 Final

                                       32
<PAGE>

rentable area of the Building has been rendered untenantable, and whether
Landlord will terminate this Lease. If Landlord elects to make any repairs or
restoration, then due allowance shall be given for the reasonable time required
for adjustment and settlement of insurance claims, time required to obtain
licenses and permits for the work, and for such other delays as may result from
government restrictions, and controls on construction, if any, and for strikes,
national emergencies and other conditions beyond the control of Landlord. If
Landlord elects to terminate this Lease in accordance with this paragraph, then
Landlord shall deliver a written notice to that effect to Tenant, specifying a
date, not less than twenty (20) nor more than sixty (60) days after the giving
of such notice, on which the Lease shall expire as fully and completely as if
such date were the date originally fixed for the expiration of the Lease.

     (C.) Adjustment of Basic Monthly Rent.  It is agreed that if Landlord does
          --------------------------------                                    
not elect to terminate this Lease pursuant to this Paragraph, this Lease shall
continue in full force and effect, but if the conditions are such so as to make
the entire Demised Premises untenantable, then all Basic Monthly Rent and
Adjustment Rent which Tenant is obligated to pay hereunder related to the period
from and after the date of the fire or casualty shall abate as of the date of
and after the fire or casualty until Landlord has substantially completed the
repairs and restoration work required to be performed by it under this Lease.
Any unpaid or prepaid Basic Monthly Rent and Adjustment Rent for the calendar
month in which said fire or casualty occurred making the Demised Premises
untenantable shall be prorated to the date of the fire or casualty giving rise
to the damage.  If the Demised Premises are partially damaged or destroyed, then
during the period that Tenant is deprived of the use of the damaged portion of
the Demised Premises, Tenant shall be required to pay Basic Monthly Rent and
Adjustment Rent covering only that portion of the Demised Premises that is
tenantable, based on that portion of the Basic Monthly Rent and Adjustment Rent
which the amount of square foot area of the Demised Premises remaining that is
tenantable bears to the total square foot area of all of the Demised Premises
covered by this Lease.

     (D.) Mutual Rights to Terminate.  If the Demised Premises are damaged as a
          --------------------------                                          
result of fire or other casualty and if the damage to the Demised Premises (but
not including the Alterations) is so extensive that, in Landlord's reasonable
judgment, such damage cannot be substantially repaired within one hundred eighty
(180) days from the date of the fire or other casualty, Landlord shall give
written notice to Tenant of such reasonable judgment within thirty (30) days of
such casualty, and either Landlord or Tenant may within thirty (30) days of the
date of such notice from Landlord, terminate the Lease by written notice to the
other, specifying a date, not less than twenty (20) nor more than sixty (60)
days after the giving of such notice, on which the Lease shall expire as fully
and completely as if such date were the date originally fixed for the expiration
of the Lease.   In the event that the Demised Premises are damaged by fire or
other casualty such that eighty percent (80%) of the Demised Premises or greater
are rendered untenantable and at the time of such damage, eighteen (18) months
or less remains of the Term of the Lease, then either Landlord or Tenant may
terminate this Lease after such casualty upon the giving to the other of ninety
(90) days prior notice, which notice shall specify the date upon which the party
giving such notice intends to terminate the Lease.  No compensation, or claim,
or diminution of rent will be allowed or paid by Landlord by reason of
inconvenience, annoyance, or loss of or injury to business arising from the
necessity of or any delays in repairing the Demised Premises or any portion of
the Building, however the necessity may occur.  Tenant shall notify Landlord of
any damage to the Demised Premises promptly upon occurrence thereof.


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June 23, 1998 Final

                                       33
<PAGE>

25.  EMINENT DOMAIN
     --------------

     (A.) Major Condemnation.  In the event that the whole or a substantial
          ------------------                                              
portion of the Building shall be condemned in any manner for any public or
quasi-public use, this Lease and the term and estate hereby granted shall
forthwith cease and terminate as of the earlier of the date of vesting of title
in such condemnation, or the date of taking of possession by the condemning
authority (such earlier date, whether with reference to a complete or partial
taking of the Building, being referred to hereinafter as the "Taking Date"), and
Tenant shall have no claim against Landlord, except that Tenant's obligation for
Basic Monthly Rent and Adjustment Rent shall cease as of the Taking Date and any
such rent paid in advance by Tenant shall be prorated to the Taking Date, with
Tenant being entitled to a refund of any excess payment thereof.

     (B.) Partial Condemnation.  In the event that only a part of the Building
          --------------------                                               
shall be so condemned, then (i) if substantial alteration or reconstruction of
the Building shall, in the opinion of Landlord, be necessary or desirable as a
result of such condemnation (whether or not the Demised Premises be affected
thereby), this Lease and the term and estate hereby granted may be terminated,
effective as of the Taking Date, by and at the exclusive option of Landlord, by
giving notice of such termination to Tenant on or before the date which is
thirty (30) days following the Taking Date, and (b) if such condemnation shall
be of a substantial part of the Demised Premises or of a substantial part of all
means of access thereto, this Lease and the term and estate hereby granted may
be terminated by Tenant, effective as of the Taking Date, by its giving notice
of such termination to Landlord on or before the date which is thirty (30) days
after the Taking Date, or (c) if neither Landlord nor Tenant elects to terminate
this Lease, as aforesaid, this Lease shall be and remain unaffected by such
condemnation or taking, except that this Lease and the term and estate hereby
granted with respect to the part of the Demised Premises (if any) so condemned
shall expire on the Taking Date, and except that the Basic Monthly Rent and
Adjustment Rent payable hereunder shall be appropriately reduced as of the
Taking Date in proportion to the area of the Demised Premises, and this Lease
and the term and estate hereby granted with respect to the remaining portion of
the Demised Premises are not terminated as hereinbefore provided, Landlord shall
proceed with reasonable diligence to restore the remaining portion of the
Demised Premises (other than Alterations, Tenant's Property, or personal
property of Tenant or others) as nearly as practicable to building standard
condition as specified in Exhibit D attached hereto.
                          ---------                

     (C.) Condemnation Award.  In the event of any condemnation of all or a part
          ------------------                                                   
of the Building and/or the Land, Landlord shall be entitled to receive the
entire award in the condemnation proceeding, including also any award made for
the value of the estate vested by this Lease in Tenant, and Tenant hereby
assigns to Landlord any and all right, title and interest of Tenant now or
hereafter arising in or to any such award or any part thereof, and Tenant shall
be entitled to receive no part of such award.  Notwithstanding the foregoing,
nothing in this Paragraph shall preclude Tenant at its own expense in a separate
action from Landlord's condemnation proceeding, to claim or receive from the
condemning authority any compensation to which Tenant may otherwise lawfully be
entitled in such case in respect of Tenant's personal property, the unamortized
amount of the cost of Tenant's Alterations,  or for moving to a new location,
provided that such award to Tenant is not derived by the condemning authority by
a reduction of the award that would otherwise be made to Landlord for the taking
of Landlord's fee simple or leasehold interest in the Demised Premises and the
Building, the Land and Landlord's interest in this Lease.


26.  SUBORDINATION
     -------------

     (A.) Subordination of Lease/General.  This Lease and all rights of Tenant
          ------------------------------                                     
hereunder are subject and subordinate to all first mortgages and first deeds of
trust, and to any other mortgages and deeds of trust junior in lien to such
first mortgage or first deed of trust if such subordination


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June 23, 1998 Final

                                       34
<PAGE>

to such junior lien is approved by the party or parties secured under such first
mortgage or first deed of trust, and to all ground or underlying leases, which
may now or hereafter affect the Building and the Land of which the Demised
Premises form a part, and all renewals, modifications, consolidations, re-
castings, replacements and extensions thereof; provided however, that subject to
the provisions of Subparagraph (B) and (C) below, this Lease shall remain in
full force and effect following any foreclosure under any of the aforesaid
mortgages, deeds of trust, or ground leases; provided, further however, that
Tenant shall not be in default beyond any applicable cure period herein. It is
the intention of the parties that this Paragraph shall be self-operative and
that no further instrument of subordination, non-disturbance or attornment shall
be necessary to effectuate such subordination nondisturbance or attornment.
However, if confirmation of such subordination, nondisturbance or attornment is
required by any mortgagee or ground lessor, Tenant shall execute and deliver
promptly upon any request of Landlord or its mortgagee(s) or ground lessor any
certificate that may be requested confirming such subordination. Tenant may not
unreasonably delay or condition its delivery. Tenant hereby constitutes and
appoints Landlord as Tenant's attorney-in-fact to execute any such certificate
or certificates for and on behalf of Tenant if Tenant fails to execute and
deliver same within seven (7) days after any request. Also the failure of Tenant
to execute and deliver such certificate or certificates shall be a default under
this Lease and basis for Landlord to exercise its rights and remedies under the
provisions of the Paragraph of this Lease entitled "DEFAULTS AND REMEDIES." Upon
                                                    ---------------------
the written request of Tenant given to Landlord, Landlord will endeavor to
obtain for Tenant a Subordination, Attornment and Non-Disturbance Agreement, on
lender's standard form, from any lender(s) placing a first mortgage or deed of
trust on the Building subsequent to the date of this Lease, other than a first
mortgage or deed of trust from Transamerica Occidental Life Insurance Company,
the current lender having an interest in the Building, which replaces, renews or
extends the currently existing first mortgage or deed of trust.

     (B.) Attornment.  The  party secured by any such mortgage or deed of trust
          ----------                                                          
or the purchaser at foreclosure thereof or by deed in lieu thereof
(collectively, "Subsequent Purchaser") shall recognize this Lease, provided,
however, that Tenant shall not be in default beyond any applicable cure period
herein, and Tenant shall attorn to and recognize the Subsequent Purchaser as its
Landlord under this Lease, and will execute, acknowledge and deliver promptly
upon request of Landlord or such mortgagee or any other Subsequent Purchaser (at
or prior to the foreclosure) any instrument which in the opinion of such party
requesting same is necessary or appropriate to evidence such attornment by
Tenant and/or the subordination of such mortgage or deed of trust to this Lease.
Also, the failure of Tenant to execute and deliver such certificate or
certificates shall be a default under this Lease and basis for Landlord to
exercise its rights and remedies under the provisions of the Paragraph of this
Lease entitled "DEFAULTS AND REMEDIES".  The Tenant hereby waives the provisions
of any statue or rule of law, now or hereafter existing, which may give or
purport to give Tenant any right to terminate or otherwise adversely affect this
Lease and Tenant's obligations hereunder in the event of any such foreclosure or
conveyance in lieu of foreclosure.  Tenant agrees that neither the cancellation
nor termination of any ground or underlying lease to which this Lease is now or
may hereafter become subject or subordinate shall by operation of law or
otherwise result in cancellation or termination of this Lease, and in such event
this Lease shall continue as a direct lease between Tenant and such ground
lessor or its successor .

     (C.) Effect of Attornment.  Notwithstanding anything to the contrary in
          --------------------                                             
this Lease, any Subsequent Purchaser and any ground lessor (i) shall not be
bound by any prepayment by Tenant to any prior lessor (including Landlord)  of
rent for more than one calendar month in advance (so that rent shall be payable
after the foreclosure, the purchase, or the termination of the ground lease, as
applicable in accordance with the terms of this Lease as if such prepayment of
rent for more than one calendar month in advance had not been made); (ii) shall
not be bound by any


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June 23, 1998 Final

                                       35
<PAGE>

amendment or modification to this Lease made without its prior written consent,
or by any waiver or forbearance on the part of any prior lessor (including
Landlord) given without its consent; (iii) shall not be liable for any act or
omission of any prior lessor (including Landlord); and (iv) shall not be subject
to any offsets or defenses which Tenant might have against any prior lessor
(including Landlord). Additionally Landlord's mortgagee shall be discharged of
any responsibility hereunder to Tenant which may have arisen (by reason of the
mortgagee becoming a mortgagee in possession, a lessor or otherwise) after such
mortgagee disposes of its interest in the Building of which the Demised Premises
is a part.

     (D.) First Amendment to Deed of Trust.  Attached hereto as Exhibit H is
          ---------------------------------                     ---------  
a true, complete and correct copy of Amendment No. 1 To First Deed of Trust,
Assignment of Rents, Security Agreement and Fixture Filing, dated as of January
12, 1998, (the "First Amendment to Deed of Trust") which has been filed of
record in the office of the Recorder of Deeds of the District of Columbia and
which affects the Building.  Landlord represents to Tenant that this First
Amendment to Deed of Trust is currently in effect.  Landlord agrees to request
from the Beneficiary under such First Amendment to Deed of Trust an agreement
setting forth provisions substantially in the form of the "SNDA Provisions", as
such term is defined in said First Amendment to Deed of Trust.

     (E.) Entitlement to Notices.  Any mortgagee or ground lessor shall be
          ----------------------                                         
entitled to receive, and Tenant shall deliver to it concurrently with Landlord,
any notices given by Tenant under this Lease provided that Landlord shall have
given Tenant the name and address of such mortgagee or ground lessor.  The
mortgagee (or purchaser therefrom), or ground lessor shall be given a reasonable
period of time following receipt of such written notice and the failure of
Landlord to cure the noticed default to cure any default(s) of Landlord which
may be claimed by Tenant.


27.  ESTOPPEL CERTIFICATES
     ---------------------

     (A.) Tenant agrees, at any time and from time to time, upon not more than
ten (10) business days' prior written notice by Landlord, to execute,
acknowledge and deliver to Landlord, or for its benefit, a statement in writing
certifying:  (i) that this Lease is unmodified and in full force and effect (or
if there have been modifications, that the Lease is in full force and effect as
modified and stating the modifications), (ii) the date to which the rent and
other charges hereunder have been paid by Tenant, (iii) whether or not to the
best knowledge of Tenant, Landlord is in default in the performance of any
covenant, agreement or condition contained in this Lease, and if so, specifying
each such default of which Tenant may have knowledge, (iv) the address to which
notices to Tenant should be sent, and (v) such other matters as are shown on
Exhibit E or which Landlord may reasonably request from time to time related to
---------                                                                     
factual matters of this Lease within Tenant's knowledge.  If Landlord makes a
request for an estoppel certificate at the request of its mortgagee or future
landlord, then Tenant shall also speak to such other matters as such mortgagee
or future landlord customarily and consistently requires of tenants similarly
situated to Tenant leasing comparable space in a first class office building to
the Building.  Any such statement delivered pursuant hereto may be relied upon
by any owner of the Building, any mortgagee or prospective mortgagee of the
Building or of Landlord's interest, or any prospective assignee of any such
mortgagee.  Tenant's failure to timely execute and deliver any estoppel
certificate shall constitute a default under this Lease, subjecting Tenant to
Landlord's rights and remedies available under the provisions of the Paragraph
of this Lease entitled "DEFAULTS AND REMEDIES."
                        --------------------- 


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June 23, 1998 Final

                                       36
<PAGE>

     (B.)   Landlord agrees to furnish to Tenant within ten (10) business days
after Tenant's written request therefor, a certificate executed by or on behalf
of Landlord containing the following statements: (i) that the Lease is
unmodified and in full force and effect (or if modified, that the Lease is in
full force and effect as modified and stating the modifications); (ii) the date
to which the rent and other charges due hereunder have been paid by Tenant;
(iii) whether or not, to Landlord's knowledge, Tenant is in default in the
performance of any covenant, agreement or condition contained in this Lease, and
if so, specifying such defaults; (iv) the address for Landlord; and (v) whether
Landlord has received written notice from Tenant claiming a default by Landlord
hereunder.  Such certificate shall not be required of Landlord more than one
time in any calendar year without Tenant having a legitimate business purpose.


28.  BANKRUPTCY
     ----------

     (A.)  Events of Bankruptcy.  Each of the following shall be an Event of
           --------------------                                            
Bankruptcy under this Lease:

          (i) Tenant's, a Guarantor's or a General Partner's becoming insolvent,
as that term is defined in Title 11 of the United States Code (the "Bankruptcy
Code"), or under the insolvency laws of any state, district, commonwealth or
territory of the United States (the "Insolvency Laws");

          (ii) The appointment of a receiver or custodian for any or all of
Tenant's, a Guarantor's or a General Partner's property or assets, or the
institution of a foreclosure action upon so material a portion of the real or
personal property of Tenant or a Guarantor or a General Partner that Landlord in
its sole, but reasonable, discretion concludes that its security under the Lease
is materially impaired;

          (iii)  The filing of a voluntary petition by Tenant, a Guarantor or a
General Partner under the provisions of the Bankruptcy Code or Insolvency Laws;

          (iv) The filing of an involuntary petition against Tenant, a Guarantor
or a General Partner as the subject debtor under the Bankruptcy Code or
Insolvency Laws, which either (a) is not dismissed within ninety (90) days of
filing, or (b) results in the issuance of an order for relief against the
debtor; or

          (v) Tenant's, a Guarantor's or a General Partner's making or
consenting to an assignment for the benefit of creditors or a common law
composition of creditors.

     (B.) Rights and Remedies.  Upon the occurrence of an Event of Bankruptcy,
          -------------------                                                
Landlord shall have all of the rights and remedies available pursuant to the
Paragraph of this Lease entitled "DEFAULTS AND REMEDIES", provided that Landlord
                                  ---------------------                        
may not exercise any of those rights and remedies while a case in which Tenant
is the subject debtor under the Bankruptcy Code is pending, if the Bankruptcy
Code prohibits the exercise of those rights and remedies by Landlord.

     (C.) Assumption or Assignment by Trustee.  If pursuant to the Bankruptcy
          -----------------------------------                               
Code this Lease shall become subject to the rights of the Trustee in Bankruptcy
(as such term is defined in the Bankruptcy Code and hereinafter called
"Trustee") to assume or assign this Lease, the Trustee shall not have the right
to assume or assign this Lease, unless the Trustee (i) promptly cures all
defaults under this Lease (other than the occurrence of the Event of
Bankruptcy), (ii) promptly compensates Landlord for any actual monetary losses
to Landlord as a result of such default, (iii) provides "adequate assurances for
future performance" under this Lease, (iv) complies with all of


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June 23, 1998 Final

                                       37
<PAGE>

the provisions of this Lease, and (v) gives appropriate written notice to
Landlord of Trustee's election to assume or reject this Lease within sixty (60)
days (or such other applicable time as provided for in the Bankruptcy Code for
assumption or rejection of this Lease) after the commencement for the action in
Bankruptcy.

     (D.) Definition of Phrase "adequate assurance of future performance".  For
          ---------------------------------------------------------------     
the purposes of the Bankruptcy Code and this Paragraph of the Lease, the phrase
"adequate assurance of future performance" shall mean that at least all of the
following criteria must have been met:

          (i) the Trustee or Tenant must pay Landlord, at the time the next
payment of Basic Monthly Rent is due under this Lease, an amount equal to the
next three (3) months of Basic Monthly Rent due under this Lease, with such
amount to be held as in accordance with the provisions of the Paragraph of this
Lease entitled "SECURITY DEPOSIT;"
                ---------------- 

          (ii) Tenant or the Trustee must agree to pay to Landlord, at any time
that Landlord is authorized to and does draw upon those funds held with Security
Deposit, the amount necessary to restore such funds to the original level
established by Subparagraph (D.)(i) above of this Paragraph;

          (iii)  Tenant or the Trustee must agree to timely pay Additional Rent
as and when due pursuant to the provisions for this Lease, and additionally
agree to pay in advance for performance of any services specially requested by
Tenant (or the Trustee) pursuant to this Lease;

          (iv) the Trustee must agree that Tenant's business shall be conducted
in a first-class manner, with no liquidation sales, auctions or the like
conducted on the Demised Premises;

          (v) the Trustee must agree that the use of the Demised Premises will
remain unchanged from that specifically permitted by this Lease; and

          (vi) the Trustee must agree that the assumption or assignment of this
Lease will not violate or affect the rights of other tenants in the Building.

     (E.) Failure to Satisfy Obligations.  In the event Tenant is unable or
          ------------------------------                                  
unwilling (i) to cure its default(s), (ii) to reimburse Landlord for Landlord's
actual monetary losses, (iii) to pay Basic Monthly Rent or Adjustment Rent when
due under this Lease, or any Additional Rent provided for when due under this
Lease, or (iv) to have the criteria imposed to establish "adequate assurance of
future performance" met, then Tenant agrees in advance that Tenant has not met
its burden of performance under this Paragraph, and this Lease and Tenant's
right to possession hereunder may be terminated by Landlord in accordance with
the provisions of the Paragraph of this Lease entitled "DEFAULTS AND REMEDIES".
                                                        ----------------------


29.  LANDLORD'S RIGHT TO CURE TENANT'S DEFAULT
     -----------------------------------------

     If Tenant defaults in the making of any payment to any third party, or the
doing of any act required to be made or done by Tenant (including the
performances of Tenant's obligations under this Lease), relating to the Demised
Premises, and such failure continues for ten (10) days after notice to Tenant,
except in an emergency where no such notice shall be required,  then Landlord
may, but shall not be required to, make such payment or do such act, and the
amount of the expense thereof, if made or done by Landlord, with interest
thereon at a rate equal to three (3) percentage points above the then applicable
base rate of interest (or comparable rate of interest) per annum as fixed by
NationsBank, National Association or such other federally chartered


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June 23, 1998 Final

                                       38
<PAGE>

financial institution as reasonably selected by Landlord, accruing from the date
paid by Landlord, shall be paid by Tenant to Landlord and shall constitute
Additional Rent hereunder due and payable by Tenant upon receipt of a written
statement of costs from Landlord. The making of such payment or the doing of
such act by Landlord shall not operate as a waiver or cure of Tenant's default,
nor shall it prevent Landlord from the pursuit of any remedy to which Landlord
would otherwise be entitled.


30.  DEFAULTS AND REMEDIES
     ---------------------

     (A.) Events of Default.  If Tenant shall (i) fail to pay the rent of any
          -----------------                                                 
kind or nature provided for in this Lease, or any installments or payments
thereof as provided herein, at the time the same shall become due and payable,
or any Additional Rent when and as due as herein provided and in either case,
such failure continues for ten (10) days after notice from Landlord or
Landlord's agent of such failure; (ii) violate or fail or neglect to keep and
perform any of the other covenants, conditions and agreements herein contained
on the part of Tenant to be kept and performed and such failure continues for a
period of ten (10) days after notice to Tenant or such longer period of time as
is reasonably necessary to cure such failure, so long as Tenant commences to
cure within such ten (10) days, is diligently and continuously pursuing such
cure and such cure is completed to Landlord's satisfaction by a date not later
than forty-five (45) days after notice to Tenant of such failure, or (iii)
abandon, vacate or desert the Demised Premises for a period in excess of thirty
(30) business days, or if Tenant's estate hereby created shall be taken upon
execution or other process of law or if an Event of Bankruptcy shall occur,
then, and in each and every such event from thenceforth, and at all, times
thereafter, at the option of Landlord, (and in addition to and not in limitation
of Landlord's right to distrain for rent, and other remedies), this Lease and
Tenant's right of possession shall thereupon cease and terminate (subject to any
restrictions imposed by the Bankruptcy Code).  Upon the termination of the
Lease, Landlord shall be entitled to possession of the Demised Premises and to
re-enter the same and remove all persons and property therefrom, without demand
of rent or demand of possession of said Demised Premises.  Landlord may
forthwith proceed to recover possession of the Demised Premises with or without
process of law, any statutory or other notice to quit or of intention to re-
enter the same being hereby expressly waived by Tenant.  In the event of such
re-entry by process of law or otherwise, Tenant nevertheless agrees to remain
answerable for any and all damage, deficiency of loss of rent which Landlord may
sustain by such re-entry, including also reasonable attorneys' fees and court
costs incurred by Landlord to enforce or defend its rights under this Lease
and/or pursuant to law.  Landlord reserves full power, which is hereby acceded
to by Tenant, to re-let the Demised Premises for the benefit of Tenant, in
liquidation and discharge, in whole or in part, as the case may be, of the
liability of Tenant under the terms and provisions of this Lease.  Any such re-
lettings may be of all or any part of the Demised Premises, and may be for a
term or terms less than or greater than the then remaining portion of the term
of this Lease, all at Landlord's exclusive discretion.  Such re-lettings shall
be on such terms, rent and conditions as Landlord may determine, and in no event
will Tenant have any right to any excess of such net rents collected from re-
lettings over the sums payable by Tenant hereunder.  Whether or not Landlord
elects to terminate this Lease pursuant to this Paragraph, Tenant shall remain
liable for all damages, deficiencies, loss, costs and expenses in rent,
reasonable attorney's fees, court costs, brokerage commissions, and expenses
incurred in preparing the Demised Premises for re-letting (including any
necessary alteration, none of which shall be deemed to release Tenant from
liability hereunder).  Landlord shall not be liable for failure to re-let or to
collect rentals under re-lettings, nor shall Tenant be released from liability
by reason thereof.  Any damage or loss of rent sustained by Landlord may be
recovered from Tenant, at Landlord's option, at time of re-letting, or in
separate actions as said damages become determinable from re-lettings, or in a
single action deferred until expiration of the term hereof (in which case the
cause of action shall not accrue until


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June 23, 1998 Final

                                       39
<PAGE>

the stated expiration of the term hereof), or in a single action prior to the
re-letting or termination or expiration hereof. Nothing herein shall prevent
Landlord from proving in full damages for rent accrued prior to termination
hereof and not paid, and from proving under any applicable laws any amounts
allowed thereby, and recovering such sums.

     (B.) No Waiver.  It is further agreed that if under the provisions of this
          ---------                                                           
Paragraph, applicable summary process shall be served, and a compromise or
settlement thereof shall be made, such compromise or settlement shall not
constitute a waiver of any subsequent breach of any covenant, condition or
agreement herein contained shall operate as a waiver of any subsequent breach
thereof.  No provision of this Lease shall be deemed to have been waived by
Landlord or Tenant unless such waiver shall be in writing signed by Landlord or
Tenant, as applicable.  No payment by Tenant or receipt by Landlord of a lesser
amount than the amount of rent herein stipulated to be due and owing by Tenant
under this Lease shall be deemed to be other than on account of the earliest
stipulated rent, nor shall any endorsement or statement on any check or any
letter accompanying any check or payment as rent be deemed an accord and
satisfaction, and Landlord may accept such check or payment without prejudice to
Landlord's right to recover the balance of such rent or pursue any other remedy
in this Lease provided.

     (C.) Late Charges.  In the event Tenant defaults in payment of any
          ------------                                                
installment or installments of Basic Monthly Rent or Additional Rent, and if
such event of default is not corrected within ten (10) days after the notice of
such nonpayment,  Tenant shall pay to Landlord, in addition to the installment
of Basic Monthly Rent or Additional Rent in default, a late charge in an amount
equal to five cents ($0.05) for each one dollar ($1.00) in default, to
compensate Landlord for the additional expense resulting from Tenant's default.


     (D.)  INTENTIONALLY DELETED.
           ----------------------

     (E.) Rights to Injunctive Relief.  In addition to and not in limitation of
          ---------------------------                                         
the other remedies in this Lease provided, Landlord shall be entitled to the
restraint by injunction of any violation or attempted or threatened violation of
any of the terms, covenants, conditions, provisions or agreements of this Lease
to the extent permitted by applicable law.

     (F.) No Limitations on Landlord's Remedies.  The remedies of Landlord
          -------------------------------------                          
provided for in this Lease are cumulative and are not intended to be exclusive
of any other remedies to which Landlord may be lawfully entitled.  The exercise
by Landlord of any remedy to which it is entitled shall not preclude or hinder
the exercise of any other such remedy, nor constitute an election of remedies.

     (G.) Rights to Attorneys' Fees.  In the event of any material default by
          -------------------------                                         
Tenant hereunder, Tenant shall reimburse Landlord all reasonable attorneys' fees
which Landlord may incur resulting therefrom, whether or not suit shall be
brought by Landlord, together with all court costs which may be incurred, as
well as any such fees incurred related to any re-letting of the Demised Premises
in whole or in part, provided that if Tenant shall be the prevailing party in
any legal action brought by Landlord against Tenant, upon the rendering of a
final non-appealable judgment, Tenant shall be entitled to recover for the fees
of its attorneys in such amount as the court may adjudge reasonable.  All
obligations of Tenant under this provisions shall be deemed Additional Rent
hereunder.

     (H.)    Interest on Late Payments.  In the event Tenant fails to pay any
             --------------------------                                     
installment or installments of Basic Monthly Rent or Additional Rent for a
period of more than ten (10) days after the due date thereof, such overdue
payment or payments shall bear interest at the lesser of


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June 23, 1998 Final

                                       40
<PAGE>

(i) a rate per annum (the "Default Rate") which is three (3) whole percentage
points higher than the highest Prime Rate as published in the Wall Street
Journal's Money Rates Column, or if such rate is no longer published then the
rate which is three (3) whole percentage points in excess of the Prime Rate of
Nationsbank, N.A. (Washington, D.C.) or (ii) the highest non-usurious rate
permitted under the laws of the jurisdiction where the Building is located, from
the date incurred to the date of payment thereof by Tenant, which amount shall
constitute Additional Rent.


31.  REPEATED DEFAULTS
     -----------------

     If Tenant is in material default of this Lease for the same or
substantially the same reason more than twice during any twelve (12) month
period during the term of this Lease, then Tenant shall not have any right to
notice of, or any cure periods for, such repeated defaults, the terms and
conditions of Paragraph of this Lease entitled "DEFAULTS AND REMEDIES,"
                                                --------------------- 
notwithstanding.  In such event, Landlord shall have available to it and may
exercise all remedies provided for in that Paragraph of this Lease for an
uncured default.


32.  SUCCESSORS
     ----------

     It is agreed that all rights, remedies and liabilities herein given to or
imposed upon either of the parties hereto, shall extend to their respective
heirs, executors, administrators, successors and assigns except where otherwise
specifically restricted or modified in this Lease.


33.  AUTOMOBILE PARKING
     ------------------

     (A.) Parking Rights.  As of the Lease Commencement Date, Landlord agrees to
          --------------                                                       
arrange that Tenant shall have available to it of an allocation of parking
contracts for the parking facility located in and serving the Building for use
by Tenant and its employees during the term of the Lease, at the ratio of one
(1) contract for each 1,500 square feet of rentable area leased from time to
time by Tenant, provided that within sixty (60) days after the respective Lease
Commencement Date for each portion of space being leased by Tenant, Tenant
notifies Landlord in writing of the number of such allocation Tenant desires and
enters into parking contracts with the parking operator or manager of the
parking facility.  The parking contracts shall contain the same terms and
conditions as are usually contained in such contracts with other monthly parking
customers of the parking operator or manager, and the monthly rate to be paid by
Tenant shall be the prevailing monthly rate charged to other monthly parking
customers, said rate to increase and decrease as the prevailing monthly parking
rate for other monthly parking customers increases and decreases from time to
time.  In the event Tenant fails to notify Landlord or fails to execute with the
parking operator or manager the monthly parking contracts for all of the
aforesaid allocation within the sixty (60) day period, or subsequently
relinquishes in any manner any parking contract, Landlord shall be under no
obligation to seek restoration of any relinquished contract or waive Tenant's
failure to notify or subsequently execute any contract prior to expiration of
the sixty (60) day period, provided, however, that such unused allotment shall
be available to Tenant if then available from the parking garage manager.

     (B.) Use.  The use of any parking facility serving the Building by Tenant,
          ---                                                                 
and its employees, subtenants, licensees and invitees, shall be at the sole risk
and expense of such party.  In no event shall Landlord have any liability for
any damage to, theft or loss of property of such party, suffered or sustained in
or about the parking facilities.  Landlord shall not be responsible for the
actions of any operator of the parking facilities of the Building.  Tenant
agrees for itself


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June 23, 1998 Final

                                       41
<PAGE>

and others exercising rights by and through Tenant to comply with all rules and
regulations in effect from time to time governing the parking facilities of the
Building, and to timely pay all charges and fees related to the use of such
areas in accordance with the parking contracts entered into by Tenant or such
other parties.

     (C.) Termination of Parking Rights.  Upon expiration or any termination of
          -----------------------------                                       
any such parking contracts, Tenant will cause all of its automobiles and those
of its personnel to be immediately removed from the parking facility.  If this
Lease is terminated or expires, then in any such event all parking contracts of
Tenant for parking in the parking facility shall thereupon also terminate.


34.  ALTERNATIVE TELEPHONE OR TELECOMMUNICATIONS PROVIDER
     ----------------------------------------------------

     (A.) Landlord Consent Required.  In the event that Tenant wishes to utilize
          -------------------------                                            
the services of a telephone or telecommunications provider whose equipment is
not servicing the Building as of the date of Tenant's execution of this Lease
("Provider"), no such Provider shall be permitted to install its lines or other
equipment within the Building without first securing the prior written consent
of Landlord, which consent shall not be unreasonably withheld.

     (B.) Condition to Consent.  Unless all of the following conditions are
          --------------------                                            
satisfied to Landlord's satisfaction in a written agreement between Provider and
Landlord or by any other means acceptable to Landlord in its reasonable
judgment, it shall be reasonable for Landlord to refuse to give its consent:

          (i) Landlord shall incur no expense whatsoever with respect to any
aspect of Provider's provision of its services, including, without limitation,
the costs of installation, materials, and service;

          (ii) Prior to commencement of any work in or about the Building by
Provider, Provider shall supply Landlord with such written indemnities,
insurance verifications, financial statements, and such other items as Landlord
reasonably deems to be necessary to protect its financial interests and the
interest of the Building relating to the proposed activities of Provider;

          (iii)  Prior to the commencement of any work in or about the Building
by the Provider, the Provider shall agree to abide by such rules and
regulations, job site rules, and such other requirements as reasonably
determined by Landlord to be necessary to protect the interest of the Building,
the tenants in the Building, and Landlord, including, without limitation,
providing security in such form and amount as determined by Landlord;

          (iv) Landlord reasonably determines that there is sufficient space in
the Building for the placement of all of Provider's equipment and materials;

          (v) Provider is licensed and reputable;

          (vi) Provider agrees to compensate Landlord for the reasonable amount
determined by Landlord for space used in the Building for the storage and
maintenance of the Provider's equipment and for all costs that may be incurred
by Landlord in arranging for:  access by the Provider's personnel, security for
Provider's equipment, and any other such costs as Landlord may expect to incur.


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June 23, 1998 Final

                                       42
<PAGE>

     (C.) Consent Is Not Landlord Warranty.  Landlord's consent under this
          --------------------------------                               
Paragraph shall not be deemed any kind of warranty or representation by
Landlord, including, without limitation, any warranty or representation as to
the suitability, competence, or financial strength of Provider.

     (D.) Tenant Pays Expenses.  Tenant acknowledges and agrees that all
          --------------------                                         
telephone and telecommunications services desired by Tenant shall be ordered and
utilized at the sole expense of Tenant.

     (E.) Tenant Responsible for Service Interruptions.  Tenant agrees that to
          --------------------------------------------                       
the extent service by Provider is interrupted, curtailed, or discontinued
Landlord shall have no obligation or liability with respect thereto and it shall
be the sole obligation of Tenant at its expense to obtain substitute service.

     (F.) Landlord's Refusal to Consent.  Notwithstanding any provision in this
          -----------------------------                                       
Paragraph to the contrary, the refusal of Landlord to consent to any prospective
Provider shall not be deemed a default or breach by Landlord of its obligations
under this Lease unless and until Landlord is adjudicated in a final and
unappealable court decision to have acted recklessly or maliciously with respect
to its refusal.

     (G.) No Third Party Rights.  The provisions of this Paragraph may be
          ---------------------                                         
enforced solely by the Tenant and Landlord, and are not for the benefit of any
other party, specifically, without limitation, no telephone or
telecommunications provider shall be deemed a third party beneficiary of the
Lease.


35.  TENANT HOLDOVER
     ---------------

     (A.) Holdover with Consent.  If Tenant shall, with the knowledge and
          ---------------------                                         
written consent of Landlord obtained prior to the expiration of the term of this
Lease, continue to remain in the Demised Premises after the expiration of the
specified term of this Lease, then and in that event, Tenant shall, by virtue of
this Lease become a tenant by the month, otherwise subject however to all of the
terms, covenants and conditions of this Lease except as otherwise noted in this
Paragraph.  Landlord has no obligation to consent to the extension of the term
of this Lease and may refuse consent of any reason.  Landlord shall be entitled
to a monthly rental equal to the monthly installment of Basic Monthly Rent in
effect and payable for the last full calendar month of the immediately preceding
expired term of this Lease, together with any amounts otherwise characterized by
this Lease as Additional Rent, including but not limited to Adjustment Rent.
This monthly tenancy shall commence with the first calendar day following the
end of the term of this Lease.  Thereafter Tenant shall give to Landlord at
least thirty (30) days' written notice of any intention to quit the Demised
Premises, and Tenant shall be entitled to thirty (30) days' written notice from
Landlord to quit the Demised Premises, except in the event of nonpayment of rent
in advance or of the breach of any other covenant or condition of this Lease by
the Tenant, in which event the Tenant shall not be entitled to any notice to
quit, the statutory thirty (30) days' notice and all other notices to quit being
hereby expressly waived.

     (B.) Hold Over without Consent.  In the event Tenant shall wrongfully hold
          -------------------------                                           
over subsequent to the expiration of the term of this Lease, or after the
expiration of any duly given thirty (30) day notice without Landlord's prior
written consent, Tenant's occupancy shall be deemed that of a tenancy at
sufferance, and not one of month to month, but Tenant otherwise shall be subject
to all the terms, covenants and conditions of this Lease, except as modified by
this Subparagraph.  Landlord shall be entitled, in lieu of rent provided for in
Subparagraph (A.) above of this Paragraph, to demand and receive from Tenant
monthly use and occupancy payments, for


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June 23, 1998 Final

                                       43
<PAGE>

each month (or portion thereof) in which Tenant shall continue to wrongfully
holdover subsequent to the expiration of the term of this Lease or any expired
monthly tenancy period, in an amount equal to the greater of (X) one and one-
half times the sum of (i) the amount of Basic Monthly Rent payable in the last
full calendar month of the specified term of this Lease, plus (ii) the amount of
Adjustment Rent due and payable from Tenant for such month or (Y) the then
prevailing fair market rent, on a monthly basis, then being charged by Landlord
to third parties for comparable space in the Building. Landlord shall also be
entitled to all other Additional Rent, otherwise accruing under this Lease. Each
such use and occupancy payment shall be due on or before the first day of each
calendar month in which Tenant shall wrongfully hold over hereunder. In no event
shall Landlord's demand or acceptance of such use and occupancy payments be
considered to constitute an acquiescence by Landlord to the extension of the
term hereof, and Landlord shall be entitled to obtain immediate possession of
the Demised Premises irrespective of any such demand or acceptance. In the event
Tenant shall pay monthly use and occupancy payments for any calendar month
following expiration of the term hereof, such payment shall be prorated upon
Tenant's surrender of full and exclusive possession of the Demised Premises to
Landlord, free of all subtenants and any other parties claiming by, through or
under Tenant.

     (C.) Tenant Liable for Damages.  In addition to rent or payments in lieu of
          -------------------------                                            
rent provided in this Paragraph, Tenant shall be liable to Landlord for all
costs, losses, claims and liabilities (including reasonable attorneys' fees)
which Landlord may incur as a result of Tenant's failure to surrender possession
of the Demised Premises to Landlord upon the expiration or earlier termination
of the term of this Lease, or any extension thereof without Landlord's prior
consent, including costs to dispossess Tenant.


36.  RIGHTS RESERVED BY LANDLORD
     ---------------------------

     Landlord reserves the right at any time and from time to time, as often as
Landlord deems desirable, without the same constituting an actual or
constructive eviction and without incurring any liability to Tenant or otherwise
affecting Tenant's obligations under this Lease, to make changes, alterations,
additions, improvements, repairs, relocations or replacements in or to the
Building and the fixtures and equipment thereof, as well as in or to the street
entrances, halls, passages, stairways and other common facilities thereof, and
to change the name by which the Building is commonly known and/or the Building's
address.  Landlord reserves the right from time to time to install, use,
maintain, repair and replace pipes, ducts, conduits, wires and appurtenant
meters and equipment for service to other parts of the Building, above the
ceiling surfaces, below the floor surfaces, within the walls and in the central
core areas of the Demised Premises, and to relocate any pipes, ducts, conduits,
wires and appurtenant meters and equipment included in the Demised Premises
which are located in the Demised Premises or located elsewhere outside the
Demised Premises.  Landlord further reserves the right at any time to alter,
expand or reduce the parking facilities, to change the means of ingress thereto
and egress therefrom, and to impose charges for parking in such facilities.
Nothing contained herein shall be deemed to relieve Tenant of any duty,
obligation or liability with respect to making any repair, replacement or
improvement or complying with any law, order or requirement of any government or
other authority; and nothing contained herein shall be deemed or construed to
impose upon Landlord any obligation, responsibility or liability whatsoever, for
the care, supervision or repair of the Building, or any part thereof, other than
as expressly provided in this Lease.  Landlord shall exercise reasonable efforts
to minimize any interference with Tenant's use and enjoyment of the Demised
Premises and reasonable means of access to the Demised Premises in exercising
Landlord's rights under this Paragraph.


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                                       44
<PAGE>

37.  JURY TRIAL WAIVER
     -----------------

     Landlord and Tenant hereby waive trial by jury in any action, proceeding or
counterclaim brought by either of the parties hereto against the other on or in
respect of any matter whatsoever arising out of or in any way connected with
this Lease, the relationship of Landlord and Tenant hereunder, Tenant's use or
occupancy of the Demised Premises, and/or any claim of injury or damage.


38.  NOTICES
     -------

     All notices required or desired to be given hereunder by either party to
the other shall be given in writing by hand or by registered or certified mail,
return receipt requested.  Notices to the respective parties shall be addressed
as follows:

          If to Landlord:
                         c/o  LaSalle Partners Management Services, Inc.
                         Suite 2400
                         2000 Pennsylvania Ave., N.W.
                         Washington, DC   20006

                         with a copy to:

                         The George Washington University
                         Office of Vice President & Treasurer
                         2121 Eye Street, N.W.
                         Suite 701
                         Washington, DC   20052

          If to Tenant:  prior to occupancy:

                         The Corporate Advisory Board Company
                         The Watergate
                         600 New Hampshire Avenue, N.W.
                         Washington, D.C.  20037
                         Attention: Mr. Michael A. D'Amato

                         subsequent to occupancy:

                         c/o the Demised Premises
                         Attention: Mr. Michael A. D'Amato

Either party may by notice given in conformance with this Paragraph designate a
new address and/or recipient to which notices shall be directed, provided that
Landlord shall have no obligation to send any notice, request, demand, consent,
approval, or other communication required or permitted under this Lease to more
than two (2) addressees, including the Demised Premises.


39.  LIEN FOR RENT
     -------------

     In consideration of the mutual benefits arising under this Lease, Tenant
hereby grants to Landlord a lien on all property of Tenant in or on the Demised
Premises, and such property shall


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                                       45
<PAGE>

be and remain subject to the lien of Landlord for the payment of all rent agreed
to be paid by Tenant herein. Said lien shall be in addition to any lien provided
to Landlord by law. The foregoing lien of Landlord as well as any lien provided
to Landlord by law shall be subordinate to the lien of any vendor or lender
providing financing for the purchase by Tenant of the following types of
property: office equipment and leasehold improvements, or any other lender to
Tenant and Landlord agrees to execute a waiver of such lien on Landlord's
standard form at the request of Tenant or such lenders.

40.  LIMITATION ON LANDLORD'S LIABILITY
     ----------------------------------

     Landlord may freely and fully assign its interest in this Lease.  It is
expressly agreed that the obligations of the party signing this Lease as
Landlord shall only bind the party or parties from time to time owning the
Building during their respective periods of ownership thereof; the party signing
this Lease as Landlord and its successors in interest shall cease to have any
liability hereunder after they respectively cease to own the Building, and such
liability shall pass to and bind only the owner from time to time of said
Building as Landlord hereunder.  Further, the liability of Landlord hereunder
shall be solely limited to the interest of Landlord in the Building and no other
assets of Landlord, any partner of Landlord, or any other person or entity shall
be available to satisfy, or be subject to, any claims by Tenant or one claiming
through Tenant.  No partner of Landlord nor any other person or entity shall be
held to have personal liability for satisfaction of any claim or judgment
against Landlord or any partner of Landlord.


41.  COVENANTS OF LANDLORD
     ---------------------

     Landlord covenants that it has the right to make this Lease for the term
specified.  Further Landlord covenants that, if Tenant shall pay all rent and
shall perform all of the covenants, agreements and conditions specified in this
Lease to be performed by Tenant, Tenant shall, for the term of the Lease,
freely, peaceably and quietly occupy and enjoy the full possession of the
Demised Premises without molestation or hindrance by Landlord, its agents or
employees.  Entry in the Demised Premises for inspections, repairs, alterations,
improvements and installations by Landlord, its agents, employees or contractors
pursuant to the Paragraph of this Lease entitled "LANDLORD'S ACCESS" and the
                                                  -----------------        
exercise by Landlord of Landlord's rights reserved in the Paragraph of this
Lease entitled "RIGHTS RESERVED BY LANDLORD" shall not constitute a breach by
                ---------------------------                                 
Landlord of this covenant, nor entitle Tenant to any abatement or reduction of
rent.  In addition, planned activities of Landlord, whether in the form of
renovation, redecoration or rehabilitation of any area of the Building,
including the lobby, and any of the surrounding public spaces by Landlord or in
the form of organized activities, public or private, shall not be deemed
violation by Landlord of Landlord's covenant of quiet enjoyment contained in
this Paragraph benefitting Tenant.


42.  MISCELLANEOUS
     -------------

     (A.) Governing Law.  This Lease shall be governed by and construed in
          -------------                                                  
accordance with the laws of the District of Columbia.

     (B.) Severability.  If any covenant or agreement of this Lease or the
          ------------                                                   
application thereof to any person or circumstance shall be held to be invalid or
unenforceable, then and in each such event the remainder of this Lease or the
application of such covenant or agreement to any other person or any other
circumstance shall not be thereby affected, and each covenant and agreement
hereof shall remain valid and enforceable to the fullest extent permitted by
law.


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                                       46
<PAGE>

     (C.) Captions.  The captions and headings throughout this Lease are for
          --------                                                         
convenience and reference only, and the words contained in such captions shall
in no way be held or deemed to define, limit, describe, explain, modify, amplify
or add to the interpretation, construction or meaning of any provision of this
Lease.

     (D.) Pronouns.  Feminine or neuter pronouns shall be substituted for those
          --------                                                            
of masculine form, and the plural shall be substituted for the singular, in any
place or places herein in which the context may require such substitution or
substitutions.  Landlord herein for convenience has been referred to in neuter
form.

     (E.) Broker.  Tenant represents that it has dealt with no broker or agent
          ------                                                             
in connection with this Lease other than Cushman & Wakefield of Washington,
D.C., Inc., ("Tenant's Broker").   Landlord has by separate agreement recognized
LaSalle Partners Management Services, Inc. as its agent for this Lease
("Landlord's Broker") and has agreed to compensate it for services rendered
therefor.  Landlord and Tenant each represent and warrant to one another that
except as set forth herein neither of them has employed any broker, agent or
finder in carrying on the negotiations relating to this Lease.  Landlord shall
indemnify and hold Tenant harmless, and Tenant shall indemnify and hold Landlord
harmless, from and against any claim or claims for brokerage or other commission
arising from or out of any breach of the foregoing representation and warranty
by the respective indemnitors.

     (F.) Due Execution.  Each of the individuals signing this Lease on behalf
          -------------                                                      
of Tenant does hereby represent and warrant to Landlord that he, she or it has
the full right, power, capacity and authority to execute and deliver this Lease
as a binding and valid obligation of Tenant hereunder.

     (G.) No Liability.  Landlord shall not be liable to Tenant, its employees,
          ------------                                                        
agents, invitees, licensees, customers, clients, family members or guests for
any damages, compensation or claim arising from the necessity of repairing any
areas of the Demised Premises or the Building, the interruption of the use or
occupancy of the Demised Premises, accident or damage resulting from the use or
operation (by Landlord, Tenant, or any other person or persons whatsoever) of
elevators or heating cooling, electrical or plumbing equipment or apparatus; or
the termination of the Lease by reason of the destruction of the Demised
Premises; or from any fire, robbery, theft, mysterious disappearance and/or any
other casualty or from any leakage in all or any part of the Demised Premises or
the Building, or from water, rain or snow that may leak into or flow from any
part of the Demised Premises or the Building, or from drains, pipes, or plumbing
work in the Building, or from any other cause whatsoever.  Any goods, property
or personal effect, stored or placed by Tenant in or about the Demised Premises
or Building, shall be there at the risk of Tenant; it being agreed that Landlord
shall not in any manner be held responsible therefor.  The employees of Landlord
are prohibited from receiving any packages or other articles delivered to the
Building for Tenant, and if such employee receives any such package or articles,
such employee shall be the agent of Tenant for such purposes and not of
Landlord.

     (H.) Rules of Construction.  The parties acknowledge that each party and
          ---------------------                                             
its counsel have reviewed and revised this Lease, and the parties hereby agree
that the normal rule of construction to the effect that any ambiguities are to
be resolved against the drafting party shall not be employed in the
interpretation of this Lease or any amendments thereto.

     (I.)  Joint and Several Liability.  If two or more individuals,
           ---------------------------                             
corporations, partnerships or other business associations (or any combination of
two or more thereof) shall sign this Lease as Tenant, the liability of each of
them shall be joint and several.  In like manner, if Tenant is a partnership or
other business association the members of which are, by virtue of statute or
general law, subject to personal liability, the liability of each individual who
was, is or becomes a member


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                                       47
<PAGE>

of such partnership or association at any time from the date of execution of
this Lease to and including the expiration or earlier termination of the term of
this Lease, shall be joint and several.

     (J.) Corporate Tenant.  If Tenant is or will be a corporation, the persons
          ----------------                                                    
executing this Lease on behalf of Tenant hereby consent, represent and warrant
that Tenant is a duly incorporated or a duly qualified (if a foreign
corporation) corporation and authorized to do business in the District of
Columbia; and that the person or persons executing this Lease on behalf of
Tenant is an officer or are officers of Tenant, and that he or they as such
officers are duly authorized to sign and execute this Lease.  Upon request of
Landlord to Tenant, Tenant shall deliver to Landlord documentation satisfactory
to Landlord evidencing Tenant's compliance with the provisions of this
Paragraph. Further, Tenant agrees to promptly execute all necessary and
reasonable applications or documents confirming such registration as requested
by Landlord or its representatives, required by the jurisdiction in which the
Building is located to permit the issuance of necessary permits and certificates
for Tenant's use and occupancy of the Demised Premises.  Any delay or failure by
Tenant in submitting such application or document so executed shall not serve to
delay the Lease Commencement Date or Mandatory Expansion Space Lease
Commencement Date, as applicable, or delay or waive Tenant's obligations to pay
rent hereunder.


     (K.) Financial Statements.  If required in connection with a sale or
          --------------------                                          
refinancing of the Building (alone or with other property of Landlord) Tenant
upon written request by Landlord (but not more frequently than three (3)  times
during the term of this Lease) , will provide Landlord with a copy of its most
recent financial statements, consisting of a Balance Sheet, Earnings Statement,
Statement of Changes in Financial Position, Statement of Changes in Owner's
Equity, and related footnotes (other than footnotes relating to the repurchase
of employee stock options), prepared in accordance with generally accepted
accounting principles.  Such financial statements must be either certified by a
certified public accountant or sworn to as to their accuracy by Tenant's chief
financial officer.  The financial statements provided must be as of a date not
more than 12 months prior to the date of request.  Landlord shall retain such
statements in confidence, but may provide copies to lenders and potential
lenders or purchasers or potential purchasers as required so long as the same
agree to maintain such financial statements in confidence.

     (L.) No Conversion without Consent.  Anything herein to the contrary
          -----------------------------                                 
notwithstanding, if Tenant is a limited or general partnership (or is comprised
of two (2) or more persons, individually or as co-partners), the change or
conversion of Tenant to (i) a limited liability company, (ii) a limited
liability partnership, (iii) a corporation, or (iv) any other entity which
possesses the characteristics of limited liability shall be prohibited unless
the prior written consent of Landlord is obtained, which consent may be withheld
in Landlord's sole discretion.

     (M.) No Partnership.  Landlord and Tenant shall not be deemed by virtue of
          --------------                                                      
this Lease to be partners or joint venturers, and their relationship hereby
established is deemed to be only that of lessor and lessee, respectively.

     (N.) Rule Against Perpetuities.  If and to the extent that this Lease
          -------------------------                                      
would, in the absence of the limitation imposed by this Paragraph, be invalid or
unenforceable as being in violation of the rule against perpetuity or any other
rule of law relating to the vesting of interests in property or the suspension
of the power of alienation of property, then it is agreed that notwithstanding
any other provision of this Lease, this Lease and any and all options, rights
and privileges granted to Tenant thereunder, or on connection therewith shall
terminate if not previously terminated, on the date which is twenty-one (21)
years after the death of the last heir or issue, who are lives in being as of
the date of this Lease, of the following named persons: Mr. Michael D'Amato.


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       48
<PAGE>

     (O.) Lender Approval.  INTENTIONALLY DELETED.
          ---------------                        

     (P.) Time of the Essence.  Time is of the essence regarding performance of
          -------------------                                                 
all of Tenant's and Landlord's covenants and obligations under this Lease.

     (Q.) Business Day/Working Day.  The terms "business day" and "working day"
          ------------------------                                            
are terms describing each calendar day Monday through Friday except any holiday
identified specifically or generically in the Paragraph of this Lease entitled,
"SERVICES" falling on one of such calendar days.
 --------                                      

     (R.) Amendment or Modification of This Lease.  This Lease may not be
          ---------------------------------------                       
modified or changed in whole or in part in any manner other than by an agreement
in writing duly signed by all parties hereto.

     (S.) Entire Agreement.  This Lease together with all noted Exhibits
          ----------------                                             
referred to herein, attached hereto and made a part hereof, contains and
embodies the entire agreement of the parties hereto, and no representations,
inducements or agreements, oral or otherwise between the parties not contained
and embodied in this Lease and the exhibits hereto, shall be of any force or
effect.

     (T.)    No Recording.  This Lease shall not be recorded.  This Lease shall
             -------------                                                    
not be recorded in any office legally established for the purpose of giving
public notice of real estate records and any attempt to record this Lease or any
memorandum thereof may be treated by Landlord as an immediate default under this
Lease not subject to any cure periods.  In the event Tenant does record this
Lease or any memorandum thereof, Tenant by such act irrevocably constitutes and
appoints Landlord as its special attorney-in-fact to execute any and all
documents required to remove the Lease or any memorandum thereof from the public
records.

43. TENANT'S RIGHT TO RENEW


          I. A.  Tenant is hereby granted an option to renew or extend the term
for one (1) additional period commencing on the Lease Expiration  Date  and
expiring five consecutive Lease Years thereafter  (the "Renewal Period").
Subject to the provisions of Subparagraph II below, such renewal option shall be
exercisable by Tenant by giving written notice of the exercise of such renewal
option to Landlord at least eighteen (18) months prior to the expiration of the
initial term.  In the event that Tenant exercises the option to renew this Lease
in accordance with the provisions hereof, then the term shall be extended
accordingly.   Except as otherwise expressly provided herein, the Renewal Period
shall be upon the same terms, covenants and conditions as set forth herein with
respect to the initial term, including without limitation, the provisions of
Paragraph 5 OPERATING EXPENSE INCREASES AND REAL ESTATE TAX ADJUSTMENTS  (except
            ------------------------------------------------------------       
the Operating Expense Base shall be the amount of Operating Expenses incurred,
and the Real Estate Tax Base shall be the amount of Real Estate Taxes incurred,
during the Fiscal Year in which the Renewal Period commences) except that there
shall be no abatement of any Basic Monthly Rent, there shall be no further
rights to renew, and there shall be no right to lease any Swing Space.  In the
event that Tenant renews or extends the term of this Lease, Tenant shall provide
Landlord with successive letters of credit as a security deposit in accordance
with the provisions of Paragraph 6 SECURITY DEPOSIT, provided, however that each
                                   ----------------                            
such letter of credit shall not be less than one month's Basic Monthly Rent for
the Demised Premises as then configured and provided further that this
obligation to provide each such letter of credit shall not be affected by any
other provisions of this Lease relating to a reduction in the letter of credit
serving as a Security Deposit under this Lease.  All references in this Lease to
the Term shall be construed to mean the initial term and the Renewal


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       49
<PAGE>

Period, unless the context clearly indicates that another meaning is intended.
For purposes of this Lease, no distinction is made between the terms "extend"
and "renew," or any variations thereof.

          B.  The Basic Annual Rent for the Demised Premises payable pursuant to
Paragraph 3 RENT/BASIC ANNUAL RENT during each Lease Year of each Renewal Period
            ----------------------
shall be equal to the Fair Market Value Rate (as defined below in subparagraph
D.) for such Lease Year as of the commencement of such Renewal Period multiplied
by the rentable area of the Demised Premises.

          C.  Within thirty (30) days after Tenant's exercise of the renewal
option, but no earlier than twelve (12) months prior to the expiration of the
then current term, Landlord shall send to Tenant a written notice specifying the
Fair Market Value Rates for each Lease Year during the Renewal Period as
determined by Landlord in accordance with Paragraph 43 D.  Within thirty (30)
days after receipt of such notice from Landlord, Tenant shall send Landlord a
written notice of Tenant's acceptance or challenge of Landlord's determination
of the Fair Market Value Rates, provided, however, that in the event that Tenant
fails to respond within such thirty (30) day period, Tenant shall be deemed to
have accepted Landlord's determination of the Fair Market Value Rates.  In the
event that Tenant challenges Landlord's determination of the Fair Market Value
Rates and Landlord and Tenant are not able to agree on such rates within thirty
(30) days (the "Negotiation Period") after Tenant notifies Landlord of Tenant's
challenge of Landlord's determination of such Fair Market Value Rates, then
Landlord and Tenant shall each, within fifteen (15) days after the expiration of
the Negotiation Period, select a representative, each of whom shall be a
licensed real estate broker with at least ten (10) years' experience in the
Washington, D.C. office market who shall determine the Fair Market Value Rates
in accordance with Subparagraph I.D.  The representatives of Landlord and
Tenant, respectively, shall be instructed to complete the appraisal procedure
and to submit their written determinations to Landlord and Tenant within fifteen
(15) days after their meeting.  In the event that the determination of the Fair
Market Value Rates submitted by Landlord's representative is equal to or less
than one hundred ten percent (110%) of the determination of the Fair Market
Value Rates submitted by Tenant's representative, the Fair Market Value Rates
shall be the average of such determinations.  If the determination of the Fair
Market Value Rates submitted by Landlord's representative is greater than one
hundred ten percent (110%) of the determination of the Fair Market Value Rates
submitted by Tenant's representative, the Landlord's and Tenant's respective
representatives shall, within ten (10) days, appoint a third individual with
similar qualifications to make such determination of the Fair Market Value
Rates.  In the event that the Landlord's representative and the Tenant's
representative cannot agree as to the selection of the third person to perform
the determination of Fair Market Value Rates within ten (10) days after Landlord
and Tenant are notified of the determination of their respective
representatives, either party may request that the President of the Greater
Washington Commercial Association of Realtors (or any successor organization)
appoint the third individual to determine the Fair Market Value Rates. This
third individual shall be instructed to complete the appraisal procedure and to
submit a written determination of the Fair Market Value Rates to Landlord and
Tenant within fifteen (15) days after such individual's appointment.  The
determination which is neither the highest nor the lowest of the three
determinations shall be binding upon Landlord and Tenant as the Fair Market
Value Rates, provided, however, that in the event that the determination of the
third individual is exactly the same as the determination of Landlord's
representative or exactly the same as the determination of Tenant's
representative, then in such case, the determination of the third individual
appointed to determine the Fair Market Value Rates shall be binding upon
Landlord and Tenant as the Fair Market Value Rates.  Landlord and Tenant shall
each bear the costs of their respective representatives.  The expenses of the
third individual appointed to determine Fair Market Value Rates shall be borne
one-half (1/2) by Landlord and one-half (1/2) by Tenant.


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       50
<PAGE>

          D.  For purposes of this Lease, the term "Fair Market Value Rate"
means the fair market rental rate per square foot of rentable area of the
Demised Premises that would be agreed upon between a landlord and a tenant
executing a lease in a comparable building of comparable quality in a comparable
location, assuming the following;  (1) the landlord and tenant are typically
motivated; (2) the landlord and tenant are well informed and well advised and
each is acting in what it considers its own best interest; (3) the rental rate
takes into account all concessions, special financing amounts and/or terms,
unusual services, fees, costs and credits in connection with the leasing
transaction; (4) the Demised Premises are to be let with vacant possession and
subject to the provisions of this Lease, and (5) market rents then being charged
for comparable space in other similar office buildings in comparable locations
in Washington, D.C.

     II.  The Renewal Option referred to in Subparagraph I above may not be
exercised by Tenant if, at the time specified for exercising such option, this
Lease shall not be in full force and effect, Tenant shall have sublet in excess
of 10,000 square feet of rentable area of the Demised Premises, or in the event
that Tenant, at the time Tenant exercises such option, shall be in default in
the performance of any obligations hereunder.  If Tenant shall fail to exercise
such option during the time or in the manner provided in this Paragraph 43 for
the exercise thereof, or if at the time specified for the exercise of such
option, Tenant shall not be entitled to exercise such option because of the
provisions of this Subparagraph II, then, and in either such event, such option
shall be absolutely void and of no force and effect.

44.  EXPANSION OPTIONS
     -----------------

          (a) Tenant shall have the option to lease the following:

          1) approximately 21,661 square feet of net rentable area on the third
floor of the Building  as shown on Exhibit A (the "Expansion Space A") on March
                                   ---------                                  
23, 1999. Tenant shall have the option to lease all, but not less than all, of
such Expansion Space A on the terms and conditions hereinafter set forth;

          2) approximately 4,958 square feet of net rentable area on the second
floor as shown on Exhibit A (the "Expansion Space B") on  July 1, 1999.  Tenant
                  ---------                                                   
shall have the option to lease all, but not less than all, of such Expansion
Space B on the terms and conditions hereinafter set forth; and

          3) approximately 9,936 square feet of net rentable area on the seventh
floor of the Building as shown on Exhibit A (the "Expansion Space C"), on
                                  ---------                             
January 1, 2004 or earlier, as provided hereinbelow. Tenant shall have the
option to lease all, but not less than all, of such Expansion Space C on the
terms and conditions hereinafter set forth.  If such Expansion Space C becomes
available for lease prior to January 1, 2004, then Tenant's right to lease all,
but not less than all of such Expansion Space C shall take effect upon written
notice from Landlord that such Expansion Space C has become available to lease.

Landlord shall have no liability to Tenant in the event any or all of Expansion
Space A, Expansion Space B, or Expansion Space C are not available for lease on
the dates set forth hereinabove.  If any existing tenant of Expansion Space A or
Expansion Space B or Expansion Space C or occupant of the foregoing expansion
spaces holds over in violation of its lease such that the respective expansion
space is not available for lease on the dates set forth hereinabove, Landlord
shall promptly initiate and pursue appropriate legal action to evict such tenant
or occupant from the affected expansion space.


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       51
<PAGE>

     (i) As to Expansion Space A,  Tenant has exercised  its option for
Expansion Space A by  giving written notice thereof to Landlord not later than
June 22, 1998, time being of the essence.  Tenant shall lease the Expansion
Space A on the same terms and conditions as the Demised Premises, including,
without limitation, the obligation to pay Additional Rent for Expansion Space A,
except that there shall be no rent abatement and the Basic Annual Rent shall be
Twenty-nine Dollars ($29.00) per rentable square foot for the first and second
Lease Years of the term of this Lease, subject to annual increases during the
term of the Lease, in accordance with the schedule set forth hereinbelow.
Tenant's Real Estate Tax Share after Expansion Space A has been added to the
Demised Premises will increase by an additional 5.9775% and Tenant's Operating
Expense Share after Expansion Space A has been added to the Demised Premises
shall be increased by an additional 7.4052%.   Tenant and Landlord shall enter
into an amendment to this Lease at the time Tenant exercises its option for
Expansion Space A to reflect the terms and conditions for the lease of such
Expansion Space A, as set forth herein.

     Tenant's Basic Rent for Expansion Space A shall be as follows:


<TABLE>
<CAPTION>


LEASE
YEAR                 BASIC ANNUAL     BASIC        BASIC
RENT PER                ANNUAL       MONTHLY
SQUARE FOOT              RENT         RENT
<S>                  <C>           <C>          <C>

          1 and 2          $29.00  $628,169      $52,347.42

          3                $29.58  $640,732.38   $53,394.37

          4                $30.17  $653,512.37   $54,459.36

          5                $30.77  $666,508.97   $55,542.41

          6                $31.39  $679,938.79   $56,661.57

          7                $33.39  $723,260.79   $60,271.73

          8                $34.06  $737,773.68   $61,481.14

          9                $34.74  $752,503.14   $62,708.60

         10                $35.43  $767,449.23   $63,954.10

         11                $36.14  $782,828.54   $65,235.71

</TABLE>



     (ii) As to Expansion Space B, Tenant shall exercise its option for
Expansion Space B by  giving written notice thereof to Landlord not later than
October 1, 1998.  Tenant shall lease the Expansion Space B on the same terms and
conditions as the Demised Premises, including, without limitation, the
obligation to pay Additional Rent for Expansion Space B, except that there shall
be


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       52
<PAGE>

no rent abatement and Basic Annual Rent shall be an amount equal to the product
of the number of square feet of rentable area attributable to Expansion Space B,
multiplied by the then applicable per-square-foot Basic Annual Rent attributable
to Expansion Space A (whether or not Tenant elects to lease Expansion Space A)
in effect for each Lease Year of the remainder of the term of this Lease,
beginning with the Lease Year in which Expansion Space B is added to the Demised
Premises, and further, to pay that Annual Basic Rent in equal monthly
installments to Landlord with the Basic Monthly Rent paid for the Demised
Premises. Tenant's Real Estate Tax Share after Expansion Space B has been added
to the Demised Premises will increase by an additional 1.3682% and Tenant's
Operating Expense Share after Expansion Space B has been added to the Demised
Premises shall be increased by an additional 1.6950%. Tenant shall deliver to
Landlord an additional security deposit in the amount of one full month's Basic
Monthly Rent for Expansion Space B at the time Tenant exercises its option for
Expansion Space B notwithstanding any other provision of this Lease relating to
any reduction in the letter of credit serving as a Security Deposit hereunder.
Tenant and Landlord shall enter into an amendment to this Lease at the time
Tenant exercises its option for Expansion Space B to reflect the terms and
conditions for the lease of such Expansion Space B, as set forth herein. In the
event that Tenant does not exercise its option for Expansion Space B within the
applicable time period required by this Paragraph, Landlord shall be free to
lease all or any part of Expansion Space B to any other person or entity on such
terms and conditions that Landlord determines in Landlord's sole discretion, and
Tenant's rights under this Paragraph 44 with respect to the Expansion Space B
shall terminate.

     (iii) As to Expansion Space C, Tenant shall exercise its option for
Expansion Space C by giving written notice thereof to Landlord not later than
January 1, 2003, provided however, that in the event  Expansion Space C becomes
available for lease earlier than January 1, 2004, Tenant shall give Landlord
written notice of Tenant's election to lease Expansion Space C within the thirty
(30) day period hereinafter described.  Tenant shall lease  Expansion Space C on
the same terms and conditions as the Demised Premises, including, without
limitation, the obligation to pay Additional Rent for Expansion Space C, except
that there shall be no rent abatement and the Basic Annual Rent shall be an
amount equal to the product of the number of square feet of rentable area
attributable to Expansion Space C, multiplied by the then applicable per-square-
foot Basic Annual Rent attributable to the Initial Demised Premises in effect
for each Lease Year of the remainder of the term of this Lease beginning in the
Lease Year in which Expansion Space C is added to the Demised Premises, and
further, to pay that Annual Basic Rent in equal monthly installments to Landlord
with the Basic Monthly Rent paid for the Demised Premises.  Tenant's Real Estate
Tax Share after Expansion Space C has been added to the Demised Premises will
increase by an additional 2.7419% and Tenant's Operating Expense Share after
Expansion Space C has been added to the Demised Premises shall be increased by
an additional 3.3968 %.  Tenant shall deliver to Landlord an additional security
deposit in the amount of one full month's Basic Monthly Rent for Expansion Space
C at the time Tenant exercises its option for Expansion Space C notwithstanding
any other provision of this Lease relating to any reduction in the letter of
credit serving as a Security Deposit hereunder.  Tenant and Landlord shall enter
into an amendment to this Lease at the time Tenant exercises its option for
Expansion Space C to reflect the terms and conditions for the lease of such
Expansion Space C, as set forth herein.   In the event that Tenant does not
exercise its option for Expansion Space C within the applicable time period
required by this Paragraph, Landlord shall be free to lease all or any part of
Expansion Space C to any other person or entity on such terms and conditions
that Landlord determines in Landlord's sole discretion, and Tenant's rights
under this Paragraph 44 with respect to the Expansion Space C shall terminate.
In the event Expansion Space C becomes available to lease prior to the
anticipated availability date of January 1, 2004, then Landlord shall give
Tenant written notice of the earlier availability of Expansion Space C  (the
"Notice of Early Availability") and Tenant shall thereupon have thirty (30) days
from the date of Landlord's Notice of Early Availability to exercise its option
to lease such Expansion Space C.  The terms and conditions of the lease of such


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       53
<PAGE>

Expansion Space C under the Notice of Early Availability shall be the same as
those set forth above for Expansion Space C.    In the event that Tenant does
not exercise its option for Expansion Space C under the Notice of Early
Availability within the applicable time period required by this Paragraph for
the exercise of such option after the Notice of Early Availability, Landlord
shall be free to lease all or any part of Expansion Space C to any other person
or entity on such terms and conditions that Landlord determines in Landlord's
sole discretion, and Tenant's rights under this Paragraph 44 with respect to the
Expansion Space C shall terminate.

     (b) Effective as of the date of delivery of possession of the Expansion
Space A,  Expansion Space B and/or  Expansion Space C, (i) each such space shall
be added to and constitute a part of the Demised Premises for all purposes under
this Lease, (ii) the rentable area of the Demised Premises shall be increased by
the rentable area of the respective expansion space, and (iii) the Basic Annual
Rent shall be appropriately increased for the remainder of the then current
Lease Year and for each Lease Year thereafter by an amount equal to the net
rentable area of the respective Expansion Space multiplied by the Basic Annual
Rent per square foot then payable for the respective expansion space, as set
forth above in the tables shown in Subparagraph 44(a)(i) with respect to
Expansion Space A and Expansion Space B and as referenced in Subparagraph
44(a)(iii) for Expansion Space C,  for each such Lease Year.   Expansion Space
A, Expansion Space B and Expansion Space C shall be delivered in their
respective then "as is" condition.  Tenant's obligation to pay rent with respect
to each of  Expansion Space A, Expansion Space B and Expansion Space C shall
commence upon delivery of the respective expansion space by Landlord to Tenant.
Tenant shall not make any alterations, installations, additions or improvements
in or to any of Expansion Space A, Expansion Space B or Expansion Space C
unless Tenant complies with Paragraph 11 ALTERATIONS of this Lease .
                                         -----------               

     (c)   Tenant may not exercise its option with respect to Expansion Space A,
Expansion Space B or Expansion Space C if, at the time specified for exercising
such respective option, this Lease shall not be in full force and effect or in
the event that at the time Tenant exercises any one of the respective expansion
options, Tenant shall have sublet in excess of 10,000 square feet of rentable
area of the Demised Premises or Tenant shall be in default in the performance of
any obligations hereunder.  If Tenant shall fail to exercise any of such options
during the time or in the manner provided in this Paragraph 44 for the exercise
thereof, or if at the time specified for the exercise of such options, Tenant
shall not be entitled to exercise such options, then, and in either such event,
such options shall be absolutely void and of no force and effect.


The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       54
<PAGE>

     IN WITNESS WHEREOF, Landlord has caused these presents to be signed and
sealed in its corporate name by its duly authorized officers and its corporate
seal to be hereto affixed and duly attested to by its Secretary, and Tenant has
hereunto set his hand and seal (or Tenant has caused these presents to be signed
in its corporate name by its duly authorized officer and attorney-in-fact, and
its corporate seal to be hereto affixed and duly attested by its Secretary), all
done as of the date first above written.



                                LANDLORD:
                                --------

ATTEST:                         THE GEORGE WASHINGTON UNIVERSITY



                                By:
---------------------------        -------------------------------------
                                   Name:
                                   Title:


     (Corporate Seal)


                                TENANT:
                                ------

ATTEST:                         THE CORPORATE ADVISORY BOARD COMPANY


                                By:
---------------------------        -------------------------------------
                                Name:
                                     -----------------------------------
                                Its:
                                    ------------------------------------

     (Corporate Seal)



The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       55
<PAGE>

DISTRICT OF COLUMBIA     )    ss:

     I, __________________________________________, a Notary Public in and for
the aforesaid jurisdiction, do hereby certify that ________________________, as
attorney-in-fact for ________________________________, party to the foregoing
Agreement, who is personally well known to me as (or satisfactorily proven to
be) the person named as the attorney-in-fact in the foregoing Agreement,
personally appeared before me, and as such attorney-in-fact acknowledged said
Agreement to be the act and deed of ______________________________, a party
therein.

     Given under my hand and seal this ____ day of ____________, 1998.


                              -----------------------------
                              Notary Public

[Notarial Seal]

My Commission Expires:_________________

DISTRICT OF COLUMBIA     )    ss:

     I, __________________________________________, a Notary Public in and for
the aforesaid jurisdiction, do hereby certify that ________________________, as
attorney-in-fact for ______________________________________, party to the
foregoing Agreement, who is personally well known to me as (or satisfactorily
proven to be) the person named as the attorney-in-fact in the foregoing
Agreement, personally appeared before me, and as such attorney-in-fact
acknowledged said Agreement to be the act and deed of
______________________________, a party therein.

     Given under my hand and seal this ____ day of ____________, 1998.


                              -----------------------------
                              Notary Public

[Notarial Seal]
My Commission Expires:_________________



The Corporate Advisory Board Company Lease
June 23, 1998 Final

                                       56
<PAGE>

                                   EXHIBIT A
                                   ---------

                                      TO
                            AGREEMENT OF LEASE FOR
                     THE CORPORATE ADVISORY BOARD COMPANY
                        2000 PENNSYLVANIA AVENUE, N.W.
                            WASHINGTON, DC   20006



                    FLOOR PLANS OF THE DEMISED PREMISES AND
                    ---------------------------------------
                               EXPANSION SPACES
                               ----------------

                                       57
<PAGE>

                                   EXHIBIT B
                                   ---------

                                      TO
                            AGREEMENT OF LEASE FOR
                     THE CORPORATE ADVISORY BOARD COMPANY
                        2000 PENNSYLVANIA AVENUE, N.W.
                            WASHINGTON, DC   20006

                      DECLARATION AS TO DATE OF DELIVERY
                        AND ACCEPTANCE OF POSSESSION OF
                               DEMISED PREMISES

     Attached to and made a part of the Agreement of Lease (office), dated the
___ day of __________, 199__, entered into by and between The George Washington
University, as LANDLORD and The Corporate Advisory Board Company, as TENANT.


     LANDLORD and TENANT do hereby declare and evidence that possession of the
Demised Premises was accepted by TENANT in its "as is" condition on the ___ day
of __________, 199__.  The Lease is now in full force and effect.  For the
purpose of this Lease, the Lease Commencement Date is established as the ___ day
of __________, 199__.  As of the date of delivery and acceptance of possession
of the Demised Premises as herein set forth, there are no claims that TENANT has
against LANDLORD and there is no right of set off against rents claimed by
TENANT against LANDLORD.


     TENANT, as a corporation, a limited liability company, or a partnership,
states that its registered agent in the District of Columbia is
_________________________, having an address at _______________________________,
and that it is duly qualified to transact business and is in good standing in
the District of Columbia pursuant to District of Columbia law as of the date of
this Declaration.

                                       58
<PAGE>

                                LANDLORD:

                                THE GEORGE WASHINGTON UNIVERSITY
Attest:



                                By:
---------------------------        -------------------------------------


                                TENANT:


                                By:
                                   -------------------------------------
                                   Name:
                                   Title:

                                       59
<PAGE>

                                   EXHIBIT C
                                   ---------


                             RULES AND REGULATIONS
                             ---------------------
                             (As of ______, 199__)

     A.  The sidewalks, entries, passages, elevators, public corridors and
staircases and other parts of the Building which are not occupied by Tenant
shall not be obstructed or used for any purpose other than ingress and egress.

     B.  Tenant shall not install or permit the installation of any awnings,
shades, or other window coverings and the like, other than those approved by
Landlord in writing.

     C.  No additional locks shall be placed upon any doors of the Demised
Premises; and the doors leading to the corridors or main halls shall be kept
closed during business hours except as they may be used for ingress or egress.

     D.  Tenant shall not construct, maintain, use or operate within the Demised
Premises or elsewhere in, on or about the Building, any equipment or machinery
which produces music, sound, or noise which is audible beyond the Demised
Premises.

     E.  Electric and telephone distribution boxes must remain accessible at all
times.

     F.  Tenant shall not perform or cause to be done any work, nor install or
operate anything in the Demised Premises, which causes vibration, noise, odors,
smoke or vapors to emanate therefrom, or which might injure the Building or
annoy or disturb other tenants or occupants.  If Landlord consents to Tenant
performing any work, the same shall be done only in the evenings between 7:00
p.m. and 7:00 a.m. and not during usual business hours unless expressly approved
in advance in writing by Landlord.

     G.  No bicycles, motorcycles, motor scooters or other vehicles of any kind
shall be brought into, stored, operated or parked anywhere within the Building
or Demised Premises, or parked in front of or adjacent to or leaned against the
Building without the consent of Landlord.

     H.  Canvassing, soliciting and peddling in the Building are prohibited, and
each tenant shall cooperate to prevent same.  No animals, reptiles, fish or
birds shall be kept in or about the Demised Premises or the Building, or brought
into the entries, elevators or stairways thereof other than tropical fish and
seeing eye dogs.  All deliveries to, or shipments from, or service to, the
Demised Premises shall be conducted in such fashion and at such times as will
not unreasonably interfere with or obstruct the orderly flow of pedestrian
traffic into and out of the Building.

     I.  No cooking or baking (other than typical office cooking, e.g. cooking
in a microwave oven) shall be permitted in any portion of the Demised Premises.

     J.  Tenant covenants and agrees, at its sole cost and expense, to comply
with all present and future laws, orders, and regulations of the District of
Columbia, federal municipal and local governments, departments, commissions,
agencies and boards to the extent that they or this Lease impose on tenant
duties and responsibilities regarding the collection, sorting, separation and
recycling of trash.

                                       60
<PAGE>

                                   EXHIBIT D
                                   ---------

                        SPECIFICATIONS FOR OFFICE SPACE
                        2000 PENNSYLVANIA AVENUE, N.W.
                                WASHINGTON, DC

                       BUILDING STANDARD SPECIFICATIONS
                               FOR OFFICE SPACE
                               ----------------

     The following items are considered building standard for insurance purposes
and for purposes of any restoration obligations of LANDLORD in the event a
casualty or condemnation and of TENANT at the end of the term of the Agreement
of Lease.

     1.   Partitioning:  Adequate interior partitioning to replace TENANT's
          ------------                                                    
          existing design.  This partitioning is to be constructed of 22" steel
          studs, and 2" gypsum wallboard, floor to ceiling.

     2.   Painting:  Standard latex paint in standard building colors.
          --------                                                   

     3.   Ceiling.  Acoustical tile ceiling.
          -------                          

     4.   Doors:  One exterior door and frame per suite, to be constructed of
          -----                                                             
          solid wood.  One complete interior door and frame with hardware will
          be provided on a ratio of one door per 150 square feet of rentable
          area.  Interior doors will be wood with a painted finish, with painted
          metal frames.

     5.   Window Covering:  Building standard blinds substantially similar to
          ---------------                                                   
          those theretofore in use.

     6.   Floor Covering:  Building standard floor coverings substantially
          --------------                                                 
          similar to those theretofore in use.

     7.   Lighting:  Fully recessed fluorescent light fixtures with glare
          --------                                                      
          reducing diffusers, in amounts to provide adequate lighting at desk
          level.

     8.   Telephone and Electrical Outlets:  One 120 V duplex wall electrical
          --------------------------------                                  
          outlet per 150 square feet of rentable space, and one telephone wall
          outlet per 200 square feet of rentable space.

     9.   Electrical System Capacity:  Building standard electrical system
          --------------------------                                     
          having a capacity of five (5) watts per square foot.

     10.  Heating and Cooling System:  LANDLORD will provide base-building
          --------------------------                                     
          standard heating and cooling equipment for normal office use.

                                       61
<PAGE>

                                   EXHIBIT E
                                   ---------

                                      TO
                        AGREEMENT OF LEASE (OFFICE) FOR
                     THE CORPORATE ADVISORY BOARD COMPANY
                        2000 PENNSYLVANIA AVENUE, N.W.
                            WASHINGTON, DC   20006


                      FORM OF TENANT ESTOPPEL CERTIFICATE
                      -----------------------------------

     This Certification made this ___ day of _________________________, 19__, by
______________________________.


     WITNESSETH:

     WHEREAS, by Agreement of Lease (Office), dated _________________________
(hereinafter referred to as the "Lease") between The George Washington
University, as landlord, (hereinafter referred to as "LANDLORD"), and The
Corporate Advisory Board Company,  as tenant, (hereinafter referred to as
"TENANT"), LANDLORD leased to TENANT certain space in an office building known
by street address as 2000 Pennsylvania Avenue, N.W., Washington, D.C., for a
term and upon the terms and conditions set forth in said Lease; and

     WHEREAS, ____________________________________________________________

_________________________________________________________________ (hereinafter
called "__________") is about [to sell the Building and Land] [to disburse a
mortgage loan  to LANDLORD to be secured by a first Deed of Trust covering the
Building and Land]; and

     WHEREAS, ____________________________________________________________, as a
condition to [the sale] [making said loan], requires confirmation of lease terms
and provisions by TENANT.

     NOW, THEREFORE, TENANT intending to be legally bound hereby, states as
follows:

     1.  That the above mentioned Lease has not been changed, modified, amended
or assigned by TENANT, and that the Lease is in full force and effect, and to
TENANT's knowledge neither LANDLORD nor TENANT is in default thereof.

     2.  That TENANT has accepted and taken possession of the Demised Premises
(as defined in the Lease) leased to it pursuant to said Lease; has commenced
payment of rent at the rate and upon the terms called for in said Lease, and
certifies that the term of the Lease commenced on the ___ day of __________,
19__, and subject to __________ option(s) to renew, the original term of the
Lease will terminate on the ___ day of __________, 19__.

     3.  That to TENANT's knowledge all improvements have been fully completed
by LANDLORD in accordance with plans and specifications approved by TENANT, and
TENANT is in full and complete possession and occupancy thereof, and TENANT is
paying rent under said Lease on a current basis.

     4.  That TENANT has made no advancements for or on behalf of LANDLORD for
which it has the right to deduct from or offset against future rentals as of the
date of this Certification.

                                       62
<PAGE>

     5.  That the TENANT has not paid rent for more than the current month
during which this Certification is made.

     6.  That there are no offsets or claims to rent, nor defenses or other
offsets against or to enforcement of the Lease by LANDLORD.

     7.  That TENANT deposited with LANDLORD a Security Deposit in the form of a
letter of credit in the amount of $_______________ with LANDLORD as of the
Lease Commencement Date and that as of the date hereof the Security Deposit
amount is                      ..
          ----------------------


     IN WITNESS WHEREOF, the undersigned has executed this Certification the day
and year first above written.


ATTEST/WITNESS:                     TENANT:



-----------------------------       ----------------------------

                                       63
<PAGE>

                                   EXHIBIT F
                                   ---------


                                      TO
                        AGREEMENT OF LEASE (OFFICE) FOR
                     THE CORPORATE ADVISORY BOARD COMPANY
                        2000 PENNSYLVANIA AVENUE, N.W.
                            WASHINGTON, DC   20006


         MINIMUM STANDARDS FOR CLEANING, JANITORIAL AND CHAR SERVICES
         ------------------------------------------------------------


          CLEANING SPECIFICATIONS FOR 2000 PENNSYLVANIA AVENUE, N.W.
          ----------------------------------------------------------

OFFICE TOWER
------------

     RESTROOMS
     ---------

          Daily
          -----

          .  Clean all mirrors

          .  Clean hand basins and bright work with a non-abrasive cleaner

          .  Clean toilet seats (both sides)

          .  Clean urinals and toilet bowls using a liquid bowl cleaner and a
             toilet bowl brush, paying special attention to flush holes, under
             the rim and passage traps

          .  Clean all bright work on urinals and toilet bowls

          .  Sweep and damp mop floor

          .  Replenish towels, tissues, handsoap and feminine supplies

          .  Walls and partitions are to be free of hand prints and dust

          Weekly
          ------

          .  Damp wipe walls, partitions and louvers

          .  Pour one cup of liquid bowl cleaner solution into drains to
             eliminate sewage odor


          Monthly
          -------

          .  Machine scrub floors with germicidal solution

                                       64
<PAGE>

     OFFICES AND HALLWAYS
     --------------------

          Daily
          -----

          .  Empty and wipe clean wastepaper baskets and ashtrays

          .  Replace wastepaper basket plastic liners

          .  Dust all horizontal surfaces up to 84" in height (unobstructed
             furniture, office equipment, appliances, window sills, etc.) with a
             treated cloth or static wool duster

          .  Vacuum unobstructed areas of all rugs and carpets in office areas,
             as well as public areas

          .  Inspect unobstructed areas of all carpeted areas for spots and/or
             stains. Spots/stains should be removed immediately

          .  Dust mop all non-carpeted floor areas with a treated yarn dust mop,
             with special attention given to unobstructed areas under desks and
             furniture to prevent accumulation of dust and dirt

          .  Clean and polish all water coolers

          .  Remove all hand prints and spots from doors and light switches

          .  Dust a sufficient number of Venetian blinds so that all blinds are
             dusted every 90 days.

     Weekly
     ------

          .  Clean Wastebaskets

          .  Vacuum hard to reach and unobstructed places (under desks, chairs,
             corners, edges)

     Monthly
     -------

          .  Clean all areas around air conditioning and return air grills

    Quarterly
    ---------

          .  Dust and/or clean ledges, moldings and picture frames

     As Necessary
     ------------

          .  Tile floors refinished and buffed. Care shall be exercised in
             applying finish so as to keep it off furniture and walls. Floor
             machines shall be used in a careful manner to avoid damage to the
             walls, and furniture.

          .  Cigarette urns and ash receivers shall be cleaned and sanitized as
             necessary, and where required, the sand level shall be maintained.

                                       65
<PAGE>

          .  When floors require wet mopping, they shall be left in a streak
             free condition. Extreme care shall be exercised in all mopping as
             to avoid splashing walls and furniture.


     LANDLORD SHALL NOT BE RESPONSIBLE FOR AND SHALL NOT CLEAN ANY KITCHENS
LOCATED IN THE DEMISED PREMISES.

                                       66
<PAGE>

                                  EXHIBIT "G"

                                   GUARANTY

        THIS GUARANTY (the "Guaranty"), is made as of the day of ____ of
_____________, 1998 by the undersigned party (the "Guarantor"), having a notice
address at The Watergate, 600 New Hampshire Avenue, N.W., Washington, D.C. 20037
Attention: Michael A. D'Amato to and for the benefit of The George Washington
University (the "Landlord"), having a notice address of c/o LaSalle Partners
Management Services, Inc., Suite 2400, 2000 Pennsylvania Avenue, N.W.,
Washington, D.C 20006 and Office of Vice President & Treasurer, 2121 Eye Street,
N.W., Suite 701, Washington, D.C 20052.

        WHEREAS, the Landlord has leased to THE CORPORATE ADVISORY BOARD
COMPANY,a Delaware corporation, (the "Tenant"), under a lease dated June __,
1998 (herein called the "Lease"), certain space located in 2000 K Street, N.W.
(the "Property"),; and

        WHEREAS, Guarantor and Tenant are both currently sharing space at The
Watergate, 600 New Hampshire Avenue, N.W. ("The Watergate") and are affiliated
corporations; and

        WHEREAS, Guarantor and Tenant have exceeded the capacity of the space
at The Watergate and therefore, Guarantor has asked Tenant to relocate; and

        WHEREAS, Tenant has agreed to relocate and has executed the Lease for
space in 2000 Pennsylvania Avenue, N.W. and the Landlord under such Lease is
willing to let space to Tenant only on the condition that Guarantor agree to
execute and deliver this guaranty.

        WHEREAS, Guarantor will receive a benefit from the ability of Tenant to
relocate to the premises demised by the Lease in the form of additional space at
the site where Guarantor presently leases space, and Guarantor is therefore
willing to execute and deliver this Guaranty.

        NOW THEREFORE, in consideration of the premises, and other good and
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged the Guarantor agrees with the Landlord as follows:

        1. The Guarantor unconditionally and irrevocably guarantees that all
sums stated in the Lease to be payable by the Tenant or sums equal thereto will
be promptly paid in full when due in accordance with the Lease, and that the
Tenant will perform and

                                       1

<PAGE>

observe each and every covenant, agreement, term, and condition in the Lease
required to be performed or observed by the Tenant. Guarantor further
unconditionally and irrevocably guarantees payment to Landlord on demand any
amounts which are paid to Landlord by the Tenant pursuant to the Lease and which
are subsequently set aside as preferential transfers under Section 547 of the
Bankruptcy Code. This Guaranty is irrevocable, unconditional and absolute, and
if for any reason any such sums shall not be paid promptly when due, the
Guarantor will, promptly after notice thereof and prior to the expiration of any
period of grace provided for in said instruments for the making of payment of
any such sums, pay the same to the person entitled thereto pursuant to the Lease
regardless of (a) any defenses or rights of set-off or counterclaims which the
Tenant may have or assert against the Landlord; provided, however, that any such
payment by the Guarantor shall not constitute a waiver of any defense or claim
which the Tenant may have against the Landlord, (b) whether the Landlord shall
have taken any steps to enforce any rights against the Tenant or any other
person to collect such sum or any part thereof, (c) the termination of the Lease
or the enforcement of any other remedy thereunder as a result of the default of
the Tenant thereunder, or (d) any other condition or contingency. The Guarantor
also agrees to pay to such person such further amount as shall be sufficient to
cover the cost and expense of collecting such sums or any part thereof or of
otherwise enforcing this Guaranty, including, in any case, reasonable
compensation to its attorneys for all services rendered in connection therewith.
Upon the Tenant's failure to perform or observe any covenant, agreement, term or
condition in the Lease to be performed or observed by the Tenant, the Guarantor
will, promptly after notice thereof and prior to the expiration of any period of
grace provided for in any said instrument for the performance or observance of
the same, perform and observe the same or cause the same promptly to be
performed and observed.
2. (a) The obligations, covenants, agreements and duties of the Guarantor under
this Guaranty shall in no way be affected or impaired by reason of the happening
from time to time of any of the following, although without notice to or further
consent of the Guarantor:

        (i) the waiver by the Landlord of the performance or observance by the
Tenant, the Guarantor or any other party or parties of any of the agreements,
covenants, terms or conditions contained in the Lease or this Guaranty; or

        (ii)the extension, in whole or in part, of the time for payment by the
Tenant or the Guarantor of any sums owing or payable under the Lease or this
Guaranty, or of any other sums or obligations under or arising out of or on
account of the Lease or this Guaranty, or the renewal of the Lease or this
Guaranty; or
       
        (iii) any assignment of the Lease or subletting of the Property or any
part thereof; or
<PAGE>

        (iv) the modification or amendment (whether material or otherwise) of
any of the obligations of the Tenant or the Guarantor under the Lease or this
Guaranty; or

        (v) the doing or the omission of any of the acts referred to in the
Lease or this Guaranty (including, without limitation, the giving of any consent
referred to therein); or

        (vi) any failure, omission or delay on the part of the Landlord to
enforce, assert or exercise any right, power or remedy conferred on or available
to the Landlord in or by the Lease or the Guaranty, or any action on the part of
the Landlord granting indulgence or extension in any form whatsoever; or

        (vii) the voluntary or involuntary liquidation, dissolution, sale of all
or substantially all of the assets, marshaling of assets and liabilities,
receivership, conservatorship, insolvency, bankruptcy, assignment for the
benefit of creditors, reorganization, arrangement, composition or readjustment
of, or other similar proceeding affecting the Tenant or the Guarantor or any of
their assets; or

        (viii) the release of the Tenant or the Guarantor from the performance
or observance of any of the agreements, covenants, terms or conditions contained
in the Lease or this Guaranty by operation of law.

        (b)    Guarantor further covenants and agrees that neither its
obligation to make payment in accordance with the terms of this Guaranty nor
any remedy for the enforcement thereof shall be impaired, modified, changed,
released or limited in any manner whatsoever by any impairment, modification,
change, release or limitation of the liability of Tenant or its estate in
bankruptcy or any remedy for the enforcement thereof resulting from the
operation of any present or future provision of the Bankruptcy Reform Act of
1978 or other statute, or from the decision of any court, nor shall such
obligation or remedy for enforcement be impaired, modified, changed, released or
limited in any manner by such event of bankruptcy.

        (c) The Guarantor hereby expressly waives, to the extent not prohibited
by law, for itself and all those claiming under the Guarantor (i) any right the
Guarantor may now or hereafter have to require the Landlord to proceed first
against the Tenant upon any obligation or liability of the Tenant that is
guaranteed by the Guarantor hereunder, (ii) any right the Guarantor may now or
hereafter have to any hearing prior to the attachment of any real or personal
property of the Guarantor to satisfy the obligations of the Guarantor hereunder,
and (iii) the benefits of any present or future constitution, statute or rule of
law which exempts property from liability for debt.

   3. In the event of the rejection or disaffirmance of the Lease by the Tenant
or the Tenant's trustee in bankruptcy pursuant to bankruptcy law or any other
law affecting creditors' rights, the Guarantor will, and does hereby (without
the necessity of any further


                                       3




































<PAGE>


agreement or act), assume all obligations and liabilities of the Tenant under
the Lease to the same extent as if (a) Guarantor were originally named the
Tenant under the Lease, and (b) there had been no such rejection or
disaffirmance, and the Guarantor will confirm such assumption in writing at the
request of the Landlord upon or after such rejection or disaffirmance; the
Guarantor shall, upon such assumption (to the extent permitted by law), have all
rights of the Tenant under the Lease.

        4.   Notice of acceptance of this Guaranty and notice of any obligations
or liabilities contracted or incurred by the Tenant are hereby waived by the
Guarantor.

        5.   The Guaranty may not be modified or amended except by a written
agreement duly executed by the Guarantor with the consent in writing of the
Landlord.

        6.   The Guarantor hereby covenants and represents that (a) neither the
execution, delivery or performance of this Guaranty or the Lease, nor the
consummation of the transactions herein or therein contemplated, nor compliance
with the terms and provisions hereof or thereof conflicts or will conflict with
or result or will result in a breach of or constitutes or will constitute a
default under (i) the organizational documents or other charter documents or by-
laws, if any, of the Tenant, (ii) any law or any order, writ, injunction or
decree of any court or governmental authority or (iii) any agreement or
instrument to which the Guarantor or the Tenant is a party or by which Guarantor
or the Tenant is bound; (b) the Guarantor is not engaged in any litigation which
will or may adversely affect its ability to carry out any of the terms and
provisions of this Guaranty.

        7.   This is an unconditional guaranty of payment, not merely of
collection.  The Guarantor's liability hereunder shall be primary and not
secondary, and shall be joint and several with that of the Tenant.  The Landlord
may proceed against the Guarantor under this Guaranty without initiating or
exhausting its remedy or remedies against the Tenant, and may proceed against
the Tenant and/or the Guarantor separately or concurrently.  If more than one
party constitutes Guarantor, then all obligations and covenants set forth herein
shall be the joint and several obligations and covenants of the undersigned
parties collectively constituting Guarantor.

        8.   The Guarantor hereby warrants and represents that as of the date
hereof, there has been no material change in its financial condition from that
reflected in any financial statements previously submitted to Landlord, and
since the date of such statement, if any, the business, property and assets of
the Guarantor have not been adversely affected in any way.

        9.   If any term or provision of this Guaranty shall be determined to be
illegal or unforceable, all other terms and provisions hereof shall nevertheless
remain effective and shall be enforced to the fullest extent permitted by law.

        10.  Any notice which the Landlord may elect to send to the Guarantor
shall be binding upon the Guarantor if mailed to it at the address set forth
above or its last address

                                       4

<PAGE>


known to the Landlord, by United States Certified or Registered Mail, Return
Receipt Requested.

        11.   This Guaranty shall be construed in accordance with the laws of
the District of Columbia.  Guarantor agrees that any litigation arising out of,
or related to, this Guaranty or the Lease shall be brought in the courts of the
District of Columbia or in the United States District Court for the District of
Columbia, and the Guarantor hereby consents to the venue of such courts.
Guarantor consents to service of process and any pleading relating to any action
between Landlord and Guarantor at the Demised Premises, as defined in the Lease,
provided however, that nothing herein shall be construed as requiring such
service at the Demised Premises.

        12.   This Guaranty shall be binding upon, Guarantor, its heirs,
personal representatives, successors and assigns and shall inure to the benefit
of, Landlord, its successors and assigns.

        13.   This Guaranty shall expire on March 31, 2002 provided the
following conditions have been met:

                a.  The Tenant is not then in default under the Lease.

                b.  Guarantor has provided to Landlord audited financial
statements for The Corporate Advisory Board Company prepared by Arthur Anderson
or other national accounting firm acceptable to Landlord in its reasonable
discretion for two (2) consecutive Fiscal Years ending December 31 which show
for each such Fiscal Year that the lesser of operating income or income before
provision of income taxes (after option repurchase and non-recurring
compensation and interest income as shown on such financial statements) exceeds
ten million dollars ($10,000,000).
               
                c.  The second of the two (2) consecutive Fiscal Years referred
to above ends on December 31, 2001.
       
                d.  Landlord has confirmed, within ten (10) business days of the
submission of the financial statements referenced in b. above that for each
Fiscal year shown on such financial statements that the lesser of operating
income or income before provision of income taxes (after option repurchase and
non-recurring compensation and interest income as shown on such financial
statements) exceeds ten million dollars ($10,000,000) and that the Tenant is not
in default under the Lease.

                f.  The financial statements are delivered to Landlord no later
than March 15, 2002.

In the event that the financial statements required under subparagraph b. are
submitted for years subsequent to Fiscal Year 2001, then the Guaranty will
expire on the first day of
<PAGE>

the month following the month in which Landlord confirms the information in such
financial statements as required in subparagraph d. above.  In the event that
the financial statements for Fiscal Years 2000 and 2001 are submitted to
Landlord later than March 15, 2002, then the Guaranty will not expire until the
first day of the month following the month in which Landlord confirms the
information in the financial statements required by subparagraph d. above.

The date of the expiration of this Guaranty is referred to herein and in the
Lease as the "Burnoff Date".

     IN WITNESS WHEREOF, the Guarantor has caused this Guaranty to be executed
as of the date first above written.

                                     GUARANTOR:

Attest/Witness:                      THE ADVISORY BOARD COMPANY


                                     By:                                 (SEAL)
-----------------------------           ---------------------------------------
Assistant Secretary                       President



















                                       6

<PAGE>

DISTRICT OF COLUMBIA            )   ss:

     I, ____________________________________, a Notary Public in and for the
aforesaid jurisdiction, do hereby certify that _______________________________
_________________________________, as attorney-in-fact for ___________________
_________________________________, party to the foregoing Agreement, who is
personally well known to me as (or satisfactorily proven to be) the person named
as the attorney-in-fact in the foregoing Agreement, personally appeared before
me, and as such attorney-in-fact acknowledged said Agreement to be the act and
deed of ___________________________________________, a party therein.

     Given under my hand and seal this ____ day of ___________________, 1998.



                                     ________________________________________
                                     Notary Public


[Notarial Seal]


My Commission Expires: _______________________________



















                                      7









<PAGE>

                                   EXHIBIT H

RECORDING REQUESTED BY AND
WHEN RECORDED MAIL TO:

McDermott, Will & Emery
600 13th Street, N.W.
Suite 1200
Washington, DC  20005
Attn:  Sean P. McGuinness, Esq.


--------------------------------------------------------------------------------
                     (Space Above For Recorder's Use Only)

                              AMENDMENT NO. 1 TO
                        FIRST DEED OF TRUST, ASSIGNMENT
                       OF RENTS, SECURITY AGREEMENT AND
                                FIXTURE FILING


        This AMENDMENT NO. 1 TO FIRST DEED OF TRUST, ASSIGNMENT OF RENTS,
SECURITY AGREEMENT AND FIXTURE FILING (this "Amendment No. 1"), dated as of
January 12, 1998, by and among THE GEORGE WASHINGTON UNIVERSITY, a corporation
created by Act of Congress ("Trustor"), having an office at 2121 I Street, N.W.,
Rice Hall, 7th floor, Washington, DC 20052, TRANSAMERICA OCCIDENTAL LIFE
INSURANCE COMPANY, a California corporation ("Beneficiary"), having an office at
c/o Transamerica Realty Services, Inc., 1150 South Olive Street, Suite 2200, Los
Angeles, California 90015, and Elizabeth M. Conahan ("Trustee"), having an
office at 7500 Old Georgetown Road, Suite 800, Bethesda, Maryland 20814-6133, as
trustee for the benefit of Beneficiary.


                             W I T N E S S E T H :

        WHEREAS, pursuant to a certain FIRST DEED OF TRUST, ASSIGNMENT OF RENTS,
SECURITY AGREEMENT AND FIXTURE FILING (the "Deed of Trust") made as of June 26,
1997, by Trustor to Trustee, for the benefit of Beneficiary, for the purpose of
securing (a) the payment of an indebtedness in the amount of FORTY MILLION AND
00/100 DOLLARS ($40,000,000.00), to be paid in accordance with the terms and
with interest as set forth in a certain Secured Promissory Note dated June 26,
1997 made by Trustor to the order of Beneficiary, and all modifications,
extensions and/or renewals thereof (such Secured Promissory Note and all
additional notes referred to in (c) below are hereinafter individually and
collectively referred to as the "Note"), (b) the payment and performance of all
indebtedness and

                                         CERTIFIED TRUE COPY
                                         Tri-State Commercial Closings, Inc.

                                         By: /s/ Barb H. Kemp
                                            --------------------------------


<PAGE>

obligations of Trustor arising under the Deed of Trust, and (c) payment of any
money advanced by Beneficiary to Trustor, or its successors, with interest
thereon, evidenced by additional notes (indicating that they are so secured) or
by endorsement of the original Note, executed by Trustor or its successor,
Trustor granted, mortgaged, chattel mortgaged, bargained, sold, alienated,
enfeoffed, released, conveyed and confirmed unto Trustee, in trust, with power
of sale, all its estate, right, title and interest in, to and under certain
Mortgaged Property (as defined in the Deed of Trust), including without
limitation the real property identified on Exhibit "A" hereto; and

        WHEREAS, Trustor and Beneficiary each wish to amend the Deed of Trust as
provided herein.

        NOW, THEREFORE, in consideration of the premises and for other good and
valuable consideration, the receipt and sufficiency of which the parties hereby
acknowledge, the parties hereby agree as follows:

        1.  Section 1.16(a) of the Deed of Trust is amended and restated in its
entirety to provide as follows:

                (a)  With respect to the leases of the Mortgaged Property
        Trustor shall (i) observe and perform faithfully every obligation which
        Trustor is required to perform under the leases; (ii) use commercially
        reasonable efforts to enforce or secure the performance of, at its sole
        cost and expense, every obligation to be performed by the tenants under
        the leases, (iii) promptly give notice to Beneficiary of any notice of
        default received by Trustor from any lessee under the leases, together
        with a copy of such notice; (iv) not collect any Rents under any of the
        leases in advance of the time when the same shall be due, or anticipate
        any payments under any of the leases, except for bona fide security
        deposits not in excess of an amount equal to two (2) months' rent;
        (v) not purport or attempt to further assign any of the leases or the
        Rents (except as expressly permitted by the last sentence of the first
        paragraph of Section 1.8 hereof); (vi) except with Beneficiary's prior
                     -----------
        written consent, not waive, condone or in any manner discharge any
        tenants from their obligations under the leases other than in the
        ordinary course of business in accordance with good business practice
        for properties of the type and quality as the Mortgaged Property in the
        District of Columbia; (vii) deliver copies of all leases to Beneficiary
        within thirty (30) days of execution; (viii) appear in and defend
        against, at Trustor's sole cost and expense, any action or proceeding
        arising under, and in any manner connected with the leases, the Rents or
        the obligations, duties or liabilities of the lessor, tenants or
        guarantors thereunder; and (ix) not execute any lease for all or any
        portion of the Mortgaged Property without the prior written consent of
        Lender, unless the lease contains subordination, nondisturbance and
        attornment provisions

                                       2

<PAGE>

        substantially in the form attached hereto as Exhibit "B" (the "SNDA
                                                     -----------
        Provisions") (provided, any such lease with an affiliate of Borrower
        shall include only such subordination and attornment provisions as
        specifically directed by Lender as provided in Section 1.16(b) hereof).
                                                       ---------------        
        Provided that the lease between Trustor and any tenant contains
        provisions substantially in the form of the SNDA Provisions, such
        provisions shall be self-operative and shall be binding upon the
        Beneficiary without the necessity of executing any additional document
        or agreement.  However, if confirmation of the subordination,
        nondisturbance or attornment pursuant to the SNDA Provisions is required
        by a tenant of Trustor, Beneficiary shall execute and deliver, upon the
        request of Trustor, an agreement with such tenant setting forth
        provisions substantially in the form of the SNDA Provisions.

    2.  Section 1.16(b) of the Deed of Trust is amended and restated in its
entirety to provide as follows:

                (b)  Trustor will not enter into any lease of the Mortgaged
        Property with any affiliate of Trustor unless (i) such lease contains
        only such of those subordination and attornment provisions set forth in
        Exhibit "C" hereto, if any, as specifically directed by Lender and at
        -----------         
        Lender's sole option and (ii) such lease provides that following the
        occurrence of an Event of Default hereunder Beneficiary may terminate
        such lease upon thirty (30) days' notice to the affiliate tenant
        thereunder.

    3.  A new Section 2.13 is added to the Deed of Trust providing as follows: 

        SECTION 2.13 Access to Rear Entrance. Trustor acknowledges that
                     -----------------------            
    access to and from the rear entrance of the Building is located on adjoining
    lands of Trustor, and Trustor agrees to maintain over such adjoining lands a
    pedestrian walkway from either 21st Street, N.W., or H Street, N.W. to the
    existing rear entrance of the building commonly known as 2000 Pennsylvania
    Avenue, N.W. (the "Building") along the south side of the Mortgaged
    Property. Such walkway shall be reasonably similar to the existing such
    walkway. Upon the occurrence and during the continuance of an Event of
    Default, Beneficiary may, at its option, give notice to Trustor demanding
    that Trustor cause to be recorded in the Land Records of the District of
    Columbia a covenant permanently granting access over Trustor's adjoining
    lands for such walkway. If Trustor fails for whatever reason (including
    Trustor's inability at such time to control such adjoining lands) to cause
    such covenant to be so recorded within fifteen (15) days after receipt of
    such notice, then, notwithstanding anything in Section 3.20 to the contrary,
                                                   ------------
    Trustor shall be personally liable to Beneficiary for any loss incurred by
    Beneficiary as a result of the diminution in value of the Mortgaged Property
    resulting from the failure of the Mortgaged Property to have access to or
    from the rear entrance of the Building.

                                       3

<PAGE>

        4. Section 3.2(b) of the Deed of Trust is amended and restated in its
entirety to provide as follows:

                (b) Any notice given pursuant to Section 1.6(f), Section 1.14(b)
                                                 -------------------------------
        or Section 1.14(d) hereof which requests Beneficiary's consent to the
           ---------------   
        matters referred to in such Sections shall contain the following legend
        (and shall be ineffective if it fails to contain such legend):

                THIS NOTICE IS GIVEN PURSUANT TO SECTION ____ OF THAT CERTAIN
                FIRST DEED OF TRUST, ASSIGNMENT OF RENTS AND SECURITY AGREEMENT
                DATED AS OF JUNE 26, 1997 GIVEN BY THE GEORGE WASHINGTON
                UNIVERSITY TO TRANSAMERICA OCCIDENTAL LIFE INSURANCE COMPANY.
                THE CONSENT REQUESTED HEREBY WILL BE DEEMED TO HAVE GRANTED BY
                TRANSAMERICA IF TRANSAMERICA FAILS TO RESPOND IN WRITING TO THIS
                REQUEST WITHIN SEVEN (7) BUSINESS DAYS OF TRANSAMERICA'S RECEIPT
                HEREOF, AS MORE FULLY PROVIDED IN THE DEED OF TRUST.

        5. Section 3.20 of the Deed of Trust is amended and restated in its
entirety to provide as follows:

                SECTION 3.20. Limited Recourse. Beneficiary agrees that the
                ------------  ----------------
        assets and property available to it to collect the principal and
        interest due under the Note shall be limited to the Mortgaged Property
        and other collateral now or hereafter encumbered to secure the repayment
        of the Note, and the rents, profits, issues and proceeds thereof. No
        other asset of Trustor shall be seized or attached to satisfy any
        monetary judgment rendered on the Note. Nevertheless, the foregoing
        shall not release or impair the obligations evidenced by the Note or any
        other Loan Document or any collateral now or hereafter given to secure
        such obligations, nor shall it prevent Beneficiary from exercising any
        right or remedy available to it under the Note or any other Loan
        Document or applicable law except as expressly set out in the first
        sentence above. Furthermore, Trustor shall be fully liable to
        Beneficiary for (i) all damages suffered by Beneficiary on account of
        fraud or material misrepresentation, (ii) all liabilities of Trustor
        under that certain Environmental Indemnity Agreement of even date
        herewith given by Trustor to Beneficiary, (iii) the distribution or
        misapplication of any rental income or other income arising with respect
        to the Mortgaged Property collected by Trustor after

                                       4

<PAGE>

        the occurrence of a Default or Event of Default (as those terms are
        defined herein) to the full extent of the rental income or other income
        collected by Trustor with respect to the Mortgaged Property thereafter,
        (iv) the replacement cost of any personal property or fixtures which are
        encumbered by the Deed of Trust or any other Loan Document which are
        removed or disposed of by Trustor and not replaced as required hereunder
        or by such other Loan Document, and then to the extent of the
        replacement cost of such personal property or fixtures, (v) the
        misapplication of any proceeds to the full extent of said misapplied
        proceeds under any insurance policies or awards resulting from
        condemnation or the exercise of the power of eminent domain or by reason
        of damage or destruction to any portion of the Mortgaged Property, (vi)
        any loss to Beneficiary occasioned by (A) Trustor's failure to insure
        the Mortgaged Property or pay real estate taxes as required hereby or by
        any other Loan Document, (B) Trustor's act or omission impairing the
        validity or priority of Beneficiary's lien on the Mortgaged Property (as
        distinguished from the value of the security for the Note), or (C) a
        willful failure of Trustor to protect and preserve the security for the
        Note as provided herein and in the other Loan Documents, (vii) any loss,
        cost or expense, including attorneys' fees, incurred by Beneficiary as a
        result of Trustor's bankruptcy, (viii) the misapplication of any
        security deposits attributable to the Mortgaged Property in violation of
        any law, governmental regulation or contractual obligation applicable to
        Trustor, (ix) the collection in advance or use of any rents, issues or
        profits in violation of any covenant contained herein or in any other
        Loan Document to the full extent of such collections, (x) any loss or
        damage to Beneficiary occasioned by any other violation of law suffered
        or committed by Trustor or its agents and (xi) any amount for which
        Trustor is liable as provided in Section 2.13 hereof.  Nothing in the
                                         ------------
        foregoing sentence shall in any manner release, affect or impair the
        existence of the indebtedness evidenced by the Note or the obligations
        of Trustor under this Deed of Trust or the other Loan Documents, or the
        enforceability hereof or thereof.  This paragraph shall survive
        foreclosure of the Deed of Trust or repayment of the Note.






                                       5

<PAGE>

        IN WITNESS WHEREOF, Trustor and Beneficiary have caused this Amendment
No. 1 to the Deed of Trust to be executed by their duly authorized officers as
of the date first above written.

                                     TRUSTOR:

                                     THE GEORGE WASHINGTON UNIVERSITY
                                     a corporation created by Act of
                                     Congress


                                     By:     /s/ Louis H. Katz
                                         -------------------------------------
                                     Name:   Louis H. Katz
                                           -----------------------------------
                                     Title:  Vice President and Treasurer
                                            ----------------------------------

                                     BENEFICIARY:

                                     TRANSAMERICA OCCIDENTAL LIFE
                                     INSURANCE COMPANY


                                     By:     /s/ Matthew A. Palmer
                                         -------------------------------------
                                     Name:   Matthew A. Palmer
                                           -----------------------------------
                                     Title:  Investment Officer
                                            ----------------------------------

                                     TRUSTEE:


                                     /s/ Elizabeth M. Conahan
                                     -----------------------------------------
                                     Elizabeth M. Conahan



















                                       6

<PAGE>

                                  EXHIBIT "A"

BORROWER AND INDEMNITOR: THE GEORGE WASHINGTON UNIVERSITY

PROPERTY ADDRESS:  2000 Pennsylvania Avenue, N.W.
                   Washington, DC 20006

LEGAL DESCRIPTION OF PROPERTY:

        Lot 58 in Square 101 in the combination of lots and part of alley closed
made by The George Washington University, as per plat recorded in Liber 173 at
folio 83 of the Records of the Office of the Surveyor for the District of
Columbia.
<PAGE>

                                  EXHIBIT "B"

                          NONAFFILIATE SUBORDINATION,
                   NONDISTURBANCE AND ATTORNMENT PROVISIONS

        (A.) Subordination and Nondisturbance. This Lease and all rights of
             --------------------------------
Tenant hereunder are subject and subordinate to all first mortgages and first
deeds of trust, and to any other mortgages and deeds of trust junior in lien to
such first mortgage or first deed of trust if such subordination to such junior
lien is approved by the party or parties secured under such first mortgage or
first deed of trust, and to all ground or underlying leases, which may now or
hereafter affect the Building and the Land of which the Demised Premises form a
part, and all renewals, modifications, consolidations, recastings, replacements
and extensions thereof; provided, however, that subject to the provisions of
Subparagraphs (B.) and (C.) below this Lease shall remain in full force and
effect following and foreclosure under any of the aforesaid mortgages, deeds of
trust or ground leases; provided further, however, that Tenant shall not be in
default beyond any applicable cure period herein. It is the intention of the
parties that this Subparagraph (A.) shall be self-operative and that no further
instrument of subordination, nondisturbance or attornment shall be necessary to
effectuate such subordination, nondisturbance or attornment. However, if
confirmation of such subordination, nondisturbance or attornment is required by
any mortgagee or ground lessor, Tenant shall execute and deliver promptly upon
any request of Landlord or its mortgagee(s) or ground lessor any certificate
that may be requested confirming such subordination. Tenant may not unreasonably
delay or condition its delivery. Tenant hereby constitutes and appoints Landlord
as Tenant's attorney-in-fact to execute any such certificate or certificates for
and on behalf of Tenant if Tenant fails to execute and deliver same within seven
(7) days after any request. Also the failure of Tenant to execute and deliver
such certificate or certificates shall be a default under this Lease and basis
for Landlord to exercise its rights and remedies under the provisions of the
Paragraph of this Lease entitled "DEFAULTS AND REMEDIES."

        (B.)  Attornment.  The party secured by any such mortgage or deed of
              ----------
trust or the purchaser at foreclosure thereof or by deed in lieu thereof
(collectively "Subsequent Purchaser") shall recognize this Lease, provided,
however, that Tenant shall not be in default beyond any applicable cure period
herein, and Tenant shall attorn to and recognize the Subsequent Purchaser as its
landlord under this Lease, and will execute, acknowledge and deliver promptly
upon request of Landlord or such mortgagee or any other Subsequent Purchaser (at
or prior to the foreclosure) any instrument which in the opinion of such party
requesting same is necessary or appropriate to evidence such attornment by
Tenant and/or the subordination of such mortgage or deed of trust to this Lease.
Also the failure of Tenant to execute and deliver such certificate or
certificates shall be a default under this Lease and basis for Landlord to
exercise its rights and remedies under the provisions of the Paragraph of this
Lease entitled "DEFAULTS AND REMEDIES." The Tenant hereby waives the provisions
of any statute or
<PAGE>

rule of law, now or hereafter existing, which may give or purport to give Tenant
any right to terminate or otherwise adversely affect this Lease and Tenant's
obligations hereunder in the event of any such foreclosure or conveyance in lieu
of foreclosure. Tenant agrees that neither the cancellation nor termination of
any ground or underlying lease to which this Lease is now or may hereafter
become subject or subordinate shall by operation of law or otherwise result in
cancellation or termination of this Lease, and in such event this Lease shall
continue as a direct lease between Tenant and such ground lessor or its
successor.

        (C). Effect of Attornment. Notwithstanding anything to the contrary in
             --------------------  
this Lease, any Subsequent Purchaser and any ground lessor (i) shall not be
bound by any prepayment by Tenant to any prior lessor (including Landlord) of
rent for more than one calendar month in advance (so that rent shall be payable
after the foreclosure, the purchase, or the termination of ground lease as
applicable in accordance with the terms of this Lease as if such prepayment of
rent for more than one calendar month in advance had not been made); (ii) shall
not be bound by any amendment or modification to this Lease or by any waiver or
forbearance on the part of any prior lessor (including Landlord) which violates
the terms of Landlord's first mortgage or deed of trust; (iii) shall not be
liable for any act or omission of any prior lessor (including Landlord); and
(iv) shall not be subject to any offsets or defenses which Tenant might have
against any prior lessor (including Landlord). Additionally Landlord's
mortgagee shall be discharged of any responsibility hereunder to Tenant which
may have arisen (by reason of the mortgagee becoming a mortgagee in possession,
a lessor or otherwise) after such mortgagee disposes of its interest in the
Building of which the Demised Premises is a part.

        (D). Entitlement to Notice. Any mortgagee or ground lessor shall be
             ---------------------                  
entitled to receive, and Tenant shall deliver to it concurrently with Landlord,
any notices given by Tenant under this Lease. The mortgagee (or purchaser
therefrom), or ground lessor shall be given a reasonable period of time
following receipt of such written notice and the failure of Landlord to cure the
noticed default to cure any default(s) of Landlord which may be claimed by
Tenant.


<PAGE>

                                  EXHIBIT "C"

                            AFFILIATE SUBORDINATION
                           AND ATTORNMENT PROVISIONS
                           -------------------------

        (A.)  Subordination of Lease/General.  This Lease and all rights of
              ------------------------------
Tenant hereunder are subject and subordinate to all first mortgages and first
deeds of trust, and to any other mortgages and deeds of trust junior in lien to
such first mortgage or first deed of trust if such subordination to such junior
lien is approved by the party or parties secured under such first mortgage or
first deed of trust, and to all ground or underlying leases, which may now or
hereafter affect the Building and the Land of which the Demised Premises form a
part, and all renewals, modifications, consolidations, recasting, replacements
and extensions thereof. It is the intention of the parties that this
Subparagraph (A.) shall be self-operative and that no further instrument of
subordination shall be necessary to effectuate such subordination of this Lease.
However, if confirmation of such subordination is required by any mortgagee or
ground lessor, Tenant shall execute and deliver promptly upon any request of
Landlord or its mortgagee(s) or ground lessor any certificate that may be
requested confirming such subordination. Tenant may not reasonably delay or
condition its delivery. Tenant hereby constitutes and appoints Landlord as
Tenant's attorney-in-fact to execute any such certificate or certificates for
and on behalf of Tenant if Tenant fails to execute and deliver same within seven
(7) days after any request. Also the failure of Tenant to execute and deliver
such certificate or certificates shall be a default under this Lease and basis
for Landlord to exercise its rights and remedies under the provisions of the
Paragraph of this Lease entitled "DEFAULTS AND REMEDIES."

        (B.)  Attornment.  The party secured by any such mortgage or deed of
              ----------
trust or the purchaser at foreclosure thereof or by deed in lieu thereof
(collectively "Subsequent Purchaser") shall have the right to recognize this
Lease and, in the event of any sale under such mortgage or deed of trust, such
Subsequent Purchaser may at its option require that this Lease remain in force
thereafter. In such event, Tenant agrees that when any foreclosure of any such
mortgage or deed of trust or conveyance in lieu of foreclosure occurs, Tenant
will attorn to and recognize the Subsequent Purchaser therefrom as its landlord
under this Lease, and will execute, acknowledge and deliver promptly upon
request of Landlord or such Subsequent Purchaser at or prior to foreclosure or
sale, any instrument which in the opinion of such party aforesaid requesting
same is necessary to evidence or confirm such attornment by Tenant and/or the
subordination of this Lease to such mortgage or deed of trust of this Lease.
Tenant may not unreasonably delay or condition its delivery of such instrument.
Tenant hereby waives the provisions of any statute or rule of law, now or
thereafter existing, which may give or purport to give Tenant any right to
terminate or otherwise adversely affect this Lease and Tenant's obligations
hereunder in the event of any such foreclosure or conveyance in lieu of
foreclosure. Also the failure of Tenant to execute and deliver such certificate
or certificates shall be a default under this Lease and basis for Landlord to
exercise its rights and remedies under the provisions
<PAGE>

of the Paragraph of this Lease entitled "DEFAULTS AND REMEDIES."

        (C.)  Effect of Attornment.  Notwithstanding anything to the contrary in
              --------------------
this Lease, any Subsequent Purchaser and any ground lessor or its successor
under any such ground lease who requests such attornment, (i) shall not be
bound by any prepayment by Tenant to any prior lessor (including Landlord) of
rent for more than one calendar month in advance (so that rent shall be payable
after the foreclosure, the purchase, or the termination of ground lease as
applicable in accordance with the terms of this Lease as if such prepayment of
rent for more than one calendar month in advance had not been made); (ii) shall
not be bound by any amendment or modification to this Lease or by any waiver or
forbearance on the part of any prior lessor (including Landlord) made or given
without the written consent of Landlord's first mortgagee or ground lessor;
(iii) shall not be liable for any act or omission of any prior lessor (including
Landlord); and (iv) shall not be subject to any offsets or defenses which Tenant
might have against any prior lessor (including Landlord). Additionally
Landlord's mortgagee shall be discharged of any responsibility hereunder to
Tenant which may have arisen (by reason of the mortgagee becoming a mortgagee in
possession, a lessor or otherwise) after such mortgagee disposes of its interest
in the Building of which the Demised Premises is a part.

        (D.)  Entitlement to Notices.  Any mortgagee or ground lessor shall be
              ----------------------
entitled to receive, and Tenant shall deliver to it concurrently with Landlord,
any notices given by Tenant under this Lease. The mortgagee (or purchaser
therefrom), or ground lessor shall be given a reasonable period of time
following receipt of such written notice and the failure of Landlord to cure the
noticed default to cure any default(s) of Landlord which may be claimed by
Tenant.

<PAGE>


DISTRICT OF                    )
                               ) ss.
COLUMBIA                       )



        The foregoing instrument was acknowledged before me this 12th day of
                                                                 ----
January, 1998, by   Louis H. Katz  , Vice President & Treasurer of The George
                  -----------------  --------------------------
Washington University, a corporation by Act of Congress, on behalf of said
corporation.


        WITNESS my hand and official seal.







                                                   /s/ Lisa Porcher
                                       ---------------------------------------
                                                     Notary Public


        My commission expires:  October 31, 2002
                               ------------------







            


<PAGE>

<TABLE>
<CAPTION>
<S>                                                                                           <C>
CALIFORNIA ALL-PURPOSE ACKNOWLEDGMENT                                                                            No.
-----------------------------------------------------------------------------------------------------------------------------------
                                                                                           |  -------- OPTIONAL SECTION ---------
  State of          CALIFORNIA                       )                                     |       CAPACITY CLAIMED BY SIGNER
           ----------------------------------------- )                                     |  Though statute does not require the
                                                     )                                     |  Notary to fill in the data below,
  County of         Los Angeles                      )                                     |  doing so may prove invaluable to
            ---------------------------------------- )                                     |  persons relying on the document.
                                                                                           |
  On   Jan 16, 1998   before me,     Karen L. Klein, Notary Public                      ,  |  [ ] INDIVIDUAL
     ----------------            -------------------------------------------------------   |  [ ] CORPORATE OFFICER(S)
           DATE                  NAME, TITLE OF OFFICER - E.G., "JANE DOE, NOTARY PUBLIC   |      Investment Officer
                                                                                           |      -------------------------------
  personally appeared          Matthew A. Palmer                                        ,  |                 TITLE(S)
                      ------------------------------------------------------------------   |  [ ] PARTNER(S)   [ ] LIMITED
                                           NAME(S) OF SIGNER(S)                            |                   [ ] GENERAL
                                                                                           |  [ ] ATTORNEY-IN-FACT
  [X] personally known to me - OR - [ ] proved to me on the basis of satisfactory          |  [ ] TRUSTEE(S)
                                           evidence to be person whose name is subscribed  |  [ ] GUARDIAN/CONSERVATOR
                                           to the within instrument and acknowledged       |  [ ] OTHER:
                                           to me that he executed the same in his          |             ------------------------
               NOTARY SEAL OF              authorized capacity and that by his signature   |      -------------------------------
               KAREN L. KLEIN              on the instrument the person, or the entity     |      -------------------------------
                APPEARS HERE               upon behalf of which the person acted, exe-     |                                     
                                           cuted the instrument.                           |  SIGNER IS REPRESENTING:            
                                                                                           |  NAME OF PERSON(S) OR ENTITY(IES)   
                                                                                           |                                     
                                           WITNESS my hand and official seal.              |        Transamerica Occidental      
                                                                                           |  -----------------------------------
                                                         /s/ Karen L. Klein                |        Life Insurance Company       
                                           ----------------------------------------------  |  -----------------------------------
                                                        SIGNATURE OF NOTARY                |

  ----------------------------------------------------- OPTIONAL SECTION --------------------------------------------------------
  THIS CERTIFICATE MUST BE ATTACHED TO    TITLE OR TYPE OF DOCUMENT
  THE DOCUMENT DESCRIBED AT RIGHT:                                  -------------------------------------------------------------
                                          NUMBER OF PAGES                          DATE OF DOCUMENT
  -------------------------------------                   ------------------------                  -----------------------------
  Though the data requested here is not   SIGNER(S) OTHER THAN NAMED ABOVE
  required by law, it could prevent                                        ------------------------------------------------------
  fraudulent reattachment of this form.
-----------------------------------------------------------------------------------------------------------------------------------
                             (COPYRIGHT) 1993 NATIONAL NOTARY ASSOCIATION - 8236 Remmet Ave., P.O. Box 7184 - Canoga Park, CA 91309
</TABLE>







<PAGE>

STATE OF MARYLAND                      )
                                       ) ss.
COUNTY OF MONTGOMERY                   )



        On this 14th day of January, 1998, before me, the undersigned officer,
               ------
personally appeared Elizabeth M. Conahan, known to me (or satisfactorily proven)
to be the person whose name subscribed to the within instrument and acknowledged
that she executed the same for the purposes therein contained.


        WITNESS my hand and official seal.




                                                 /s/ Cullum D. Anthony (?)
                                          --------------------------------------
                                                       Notary Public


        My commission expires:   1/1/2000
                               ------------




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