<PAGE>

                                                                    EXHIBIT 10.1

                       MEMBERSHIP INTEREST SALE AGREEMENT

                                 BY AND BETWEEN

                                   KULEA, LLC,
                      A VIRGINIA LIMITED LIABILITY COMPANY,

                                    AS SELLER

                                       AND

                               COLUMBIA EQUITY LP,
                         A VIRGINIA LIMITED PARTNERSHIP,

                                  AS PURCHASER

<PAGE>

                                TABLE OF CONTENTS
<TABLE>
<S>                                                                                      <C>
ARTICLE I  THE SALE.............................................................          1

    1.1     Sale of Membership Interest......................................             1
    1.2     Purchase Price...................................................             1

ARTICLE II  REPRESENTATIONS AND COVENANTS.......................................          2

    2.1      Representations by Purchaser.....................................            2
    2.2      Representations by Seller........................................            3
    2.3      Seller's Indemnity...............................................            5
    2.4      Purchaser's Indemnity............................................            5
    2.5      Covenants of Purchaser...........................................            5
    2.6      Covenants of Seller..............................................            5

ARTICLE III Conditions Precedent to the Closing................................           7

    3.1      Conditions to Purchaser's Obligations............................            7
    3.2      Conditions to Seller's Obligations...............................            7

ARTICLE IV  Closing and Closing Documents.......................................          8

    4.1      Closing..........................................................            8
    4.2      Seller's Deliveries..............................................            8
    4.3      Purchaser's Deliveries...........................................            9
    4.4      Fees and Expenses; Closing Costs.................................            9
    4.5      Adjustments......................................................            9

ARTICLE V  Miscellaneous........................................................         11

    5.1      Notices..........................................................           11
    5.2      Entire Agreement; Modifications and Waivers; Cumulative Remedies.           11
    5.3      Exhibits.........................................................           12
    5.4      Successors and Assigns...........................................           12
    5.5      Article Headings.................................................           12
    5.6      Governing Law....................................................           12
    5.7      Counterparts.....................................................           12
    5.8      Survival.........................................................           12
    5.9      Severability.....................................................           12
    5.10     Attorneys' Fees..................................................           12
</TABLE>

EXHIBITS

   A         Assignment


<PAGE>

                       MEMBERSHIP INTEREST SALE AGREEMENT

      THIS MEMBERSHIP INTEREST SALE AGREEMENT (this "Agreement") is made as of
this 12th day of October, 2004 by and between Kulea, LLC, a Virginia limited
liability company ("Seller"); and Columbia Equity, LP, a Virginia limited
partnership ("Purchaser").

                                    RECITALS

      A. Carr Capital Greenbriar, LLC, a Virginia limited liability company (the
"LLC") is the owner of certain land located in Fairfax County, Virginia (the
"Land") and the office building and related improvements located thereon (the
"Improvements"), which Land and Improvements (collectively, the "Property") are
more commonly known as the Greenbriar office building.

      B. Seller is the record and beneficial owner of seventy-five percent (75%)
("Seller's Share") of the membership interests in the LLC (the "Membership
Interest"). Seller desires to sell the Membership Interest to Purchaser, on the
terms and conditions hereinafter set forth.

      C. Purchaser desires to purchase the Membership Interest from Seller, on
the terms and conditions hereinafter set forth.

      D. Immediately prior to such purchase and sale of the Membership Interest,
Carr Capital/Holualoa Greenbriar, LLC, a Virginia limited liability company,
shall liquidate and each of its members, Holualoa Greenbriar, LLC, an Arizona
limited liability company and Carr Capital Real Estate Investments, LLC, a
Virginia limited liability company, (collectively, the "Liquidating LLC
Members") shall be admitted as members of the LLC, with a Fifteen and 79/100
percent (15.79%) membership interest in the LLC and a 53/100 percent (.53%)
membership interest in the LLC, respectively (the "Liquidation Transaction").

                                    AGREEMENT

      NOW, THEREFORE, for and in consideration of the mutual covenants herein
contained, the parties hereto agree as follows:

                                   ARTICLE I
                                    THE SALE

      1.1 Sale of Membership Interest. Seller agrees to sell, transfer, assign
and convey the Membership Interest to Purchaser, and Purchaser agrees to accept
transfer of the Membership Interest pursuant to the terms and conditions set
forth in this Agreement. The Membership Interest shall be transferred to
Purchaser free and clear of all liens, encumbrances, security interests, prior
assignments or conveyances, conditions, restrictions, voting agreements, claims,
and any other matters affecting title thereto.

      1.2 Purchase Price. The purchase price (the "Purchase Price") for which
Seller agrees to sell and assign the Membership Interest to Purchaser, and which
Purchaser agrees to pay to

                                      -1-
<PAGE>

Seller, subject to the terms of this Agreement, shall be equal to the amount of
Net Cash Flow (as such term is defined in the LLC's operating agreement (the
"LLC Operating Agreement")) that Seller would be entitled to receive pursuant to
Section 3.1 of the LLC Operating Agreement upon a hypothetical sale of the
Property for a sale price of Fifteen Million Three Hundred Thousand Dollars
($15,300,000) less the principal of an accrued interest on the mortgage loan
secured by the Property (the "Mortgage Loan"). The hypothetical sale shall be
based upon the assumption that the transfer taxes and recording taxes shall not
be payable, that there is no brokerage fee and that other fees and expenses
(subject to adjustment as set forth in Section 4.5) are as set forth in Exhibit
A attached hereto.

                                   ARTICLE II
                          REPRESENTATIONS AND COVENANTS

      2.1 Representations by Purchaser. Purchaser hereby represents and warrants
to Seller that the following statements are true, correct, and complete in every
material respect as of the date of this Agreement and will be true, correct, and
complete as of the Closing Date:

            (a) Organization and Power. Purchaser is duly organized and validly
existing as a limited partnership under the laws of the Commonwealth of
Virginia, and has full right, power, and authority to enter into this Agreement
and to assume and perform all of its obligations under this Agreement; and, the
execution and delivery of this Agreement and the performance by Purchaser of its
obligations under this Agreement have been duly authorized by all requisite
action of Purchaser and require no further action or approval of Purchaser's
partners or of any other individuals or entities in order to constitute this
Agreement as a binding and enforceable obligation of Purchaser.

            (b) Noncontravention. Neither the entry into nor the performance of,
or compliance with, this Agreement by Purchaser has resulted, or will result, in
any violation of, or default under, or result in the acceleration of, any
obligation under the partnership agreement of Purchaser, or any mortgage,
indenture, lien agreement, note, contract, permit, judgment, decree, order,
restrictive covenant, statute, rule, or regulation applicable to Purchaser.

            (c) Litigation. There is no action, suit, or proceeding, pending or
known to be threatened, against or affecting Purchaser in any court or before
any arbitrator or before any federal, state, municipal, or other governmental
department, commission, board, bureau, agency or instrumentality which (i) in
any manner raises any question affecting the validity or enforceability of this
Agreement, (ii) could materially and adversely affect the business, financial
position, or results of operations of Purchaser, (iii) could materially and
adversely affect the ability of Purchaser to perform its obligations hereunder,
or under any document to be delivered pursuant hereto.

            (d) Consents. Each consent, approval, authorization, order, license,
certificate, permit, registration, designation, or filing by or with any
governmental agency or body necessary for the execution, delivery, and
performance of this Agreement or the transactions contemplated hereby by
Purchaser has been obtained.

                                      -2-
<PAGE>

            (e) Brokerage Commission. Purchaser has not engaged the services of,
nor has it or will it or Seller become liable to, any real estate agent, broker,
finder or any other person or entity for any brokerage or finder's fee,
commission or other amount with respect to the transactions described herein on
account of any action by Purchaser. Purchaser hereby agrees to indemnify and
hold Seller and its employees, directors, members, partners, affiliates and
agents harmless against any claims, liabilities, damages or expenses arising out
of a breach of the foregoing. This indemnification shall survive Closing or any
termination of this Agreement.

      2.2 Representations by Seller. Seller hereby represents and warrants unto
Purchaser that each and every one of the following statements is true, correct,
and complete in every material respect as of the date of this Agreement and will
be true, correct, and complete as of the Closing Date:

            (a) Organization and Power. Seller is duly organized, validly
existing, and in good standing as a limited liability company under the laws of
the Commonwealth of Virginia. Seller has full right, power, and authority to
enter into this Agreement and to assume and perform all of its obligations under
this Agreement; and the execution and delivery of this Agreement and the
performance by Seller of its obligations hereunder have been duly authorized by
all requisite action of Seller and require no further action or approval of
Seller's members or managers or of any other individuals or entities in order to
constitute this Agreement as a binding and enforceable obligation of Seller.

            (b) Noncontravention. Neither the entry into nor the performance of,
or compliance with, this Agreement by Seller has resulted, or will result, in
any violation of, or default under, or result in the acceleration of, any
obligation under any limited liability company agreement, operating agreement,
regulation, mortgage, indenture, lien agreement, note, contract, permit,
judgment, decree, order, restrictive covenant, statute, rule, or regulation
applicable to Seller or to the Membership Interest.

            (c) Litigation. There is no action, suit, claim, or proceeding
pending or threatened against or affecting Seller or the Membership Interest in
any court, or before any arbitrator, or before any federal, state, municipal or
other governmental department, commission, board, bureau, agency or
instrumentality which (A) in any manner raises any question affecting the
validity or enforceability of this Agreement, (B) could materially and adversely
affect the business, financial position or results of operations of Seller, (C)
could materially and adversely affect the ability of Seller to perform its
obligations hereunder, or under any document to be delivered pursuant hereto,
(D) could create a lien on the Membership Interest, any part thereof, or any
interest therein, or (E) could adversely affect the Membership Interest, any
part thereof, or any interest therein.

            (d) Good Title. (A) Seller is the sole owner of the Membership
Interest, (B) Seller has good title to the Membership Interest, (C) the
Membership Interests are free and clear of all liens, encumbrances, pledges,
voting agreements and security interests whatsoever, and (D) Seller has not
granted any other person or entity an option to purchase or a right of first
refusal

                                      -3-
<PAGE>

upon the Membership Interest nor are there any agreements or understandings
between Seller and any other person or entity with respect to the disposition of
the Membership Interest.

            (e) No Consents. Each consent, approval, authorization, order,
license, certificate, permit, registration, designation, or filing by or with,
any governmental agency or body necessary of the execution, delivery, and
performance of this Agreement or the transactions contemplated hereby by Seller
has been obtained or will be obtained on or before the Closing Date.

            (f) Tax Matters. Seller has filed within the time and in the manner
prescribed by law all federal, state, and local tax returns and reports,
including but not limited to income, gross receipts, intangible, real property,
excise, withholding, franchise, sales, use, employment, personal property, and
other tax returns and reports, required to be filed by Seller under the laws of
the United States and of each state or other jurisdiction in which Seller
conducts business activities requiring the filing of tax returns or reports. All
tax returns and reports filed by Seller are true and correct in all material
respects. Seller has paid in full all taxes of whatever kind or nature for the
periods covered by such returns. Seller has not been delinquent in the payment
of any tax, assessment, or governmental charge or deposit and has no tax
deficiency or claim outstanding, assessed, threatened, or proposed against it.
The charges, accruals, and reserves for unpaid taxes on the books and records of
Seller as of the Closing Date are sufficient in all respects for the payment of
all unpaid federal, state, and local taxes of Seller accrued for or applicable
to all periods ended on or before the Closing Date. There are no tax liens,
whether imposed by the United States, any state, local, or other taxing
authority, outstanding against Seller or any of its assets. The federal, state,
and local tax returns of Seller have not been audited, nor has Seller received
any notice of any federal, state, or local audit.

            (g) Bankruptcy with respect to Seller. No Act of Bankruptcy has
occurred with respect to Seller. As used herein, "Act of Bankruptcy" shall mean
if a party hereto or any member or manager thereof shall (A) apply for or
consent to the appointment of, or the taking of possession by, a receiver,
custodian, trustee or liquidator of itself or of all or a substantial part of
its property, (B) admit in writing its inability to pay its debts as they become
due, (C) make a general assignment for the benefit of its creditors, (D) file a
voluntary petition or commence a voluntary case or proceeding under the Federal
Bankruptcy Code (as now or hereafter in effect), (E) be adjudicated bankrupt or
insolvent, (F) file a petition seeking to take advantage of any other law
relating to bankruptcy, insolvency, reorganization, winding-up or composition or
adjustment of debts, (G) fail to controvert in a timely and appropriate manner,
or acquiesce in writing to, any petition filed against it in an involuntary case
or proceeding under the Federal Bankruptcy Code (as now or hereafter in effect),
or (H) take any action for the purpose of effecting any of the foregoing.

            (h) Brokerage Commission. Seller has not engaged the services of,
nor has it or will it or Purchaser become liable to, any real estate agent,
broker, finder or any other person or entity for any brokerage or finder's fee,
commission or other amount with respect to the transactions described herein on
account of any action by Seller. Seller hereby agrees to indemnify and hold
Purchaser and its employees, directors, members, partners, affiliates and

                                      -4-
<PAGE>

agents harmless against any claims, liabilities, damages or expenses arising out
of a breach of the foregoing. This indemnification shall survive Closing or any
termination of this Agreement.

      2.3 Seller's Indemnity. Seller agrees to indemnify and hold Purchaser,
Columbia Equity Trust, Inc., a Maryland corporation (the "REIT"), and their
respective employees, directors, members, partners, affiliates and agents
harmless of and from all liabilities, losses, damages, costs, and expenses
(including reasonable attorneys' fees) which Purchaser or the REIT may suffer or
incur by reason of any breach of Seller's representations or warranties
contained in this Agreement, and by reason of any act or cause of action
occurring or accruing prior to the Closing Date and arising from the ownership
of the Membership Interest prior to the Closing Date.

      2.4 Purchaser's Indemnity. Purchaser agrees to indemnify and hold Seller
and its employees, directors, members, partners, affiliates and agents harmless
of and from all liabilities, losses, damages, costs, and expenses (including
reasonable attorneys' fees) which Seller may suffer or incur by reason of any
breach of Purchaser's representations or warranties contained in this Agreement,
and by reason of any act or cause of action occurring or accruing subsequent to
the Closing Date and arising from the ownership of the Membership Interests or
the operation of the Property subsequent to the Closing Date.

      2.5 Covenants of Purchaser. Purchaser agrees as follows:

            (a) Further Acts. In addition to the acts, instruments and
agreements recited herein and contemplated to be performed, executed and
delivered by Purchaser and Seller, Purchaser shall perform, execute, and deliver
or cause to be performed, executed, and delivered at the Closing or after the
Closing, any and all further acts, instruments, and agreements and provide such
further assurances as Seller may reasonably require to consummate the
transactions contemplated hereunder.

      2.6 Covenants of Seller. Seller agrees as follows:

            (a) Actions Regarding Membership Interest. Except as otherwise
permitted hereby, from the date hereof until the Closing Date, Seller shall not
take any action or fail to take any action the result of which would (1) have a
material adverse effect on the Membership Interest, the Property, Seller's
ability to sell, transfer, assign and convey the Membership Interest to
Purchaser or Purchaser's ability to continue the ownership thereof after the
Closing Date or (2) would cause any of the representations and warranties
contained in Section 2.2 to be untrue as of the Closing Date.

            (b) Confidentiality. Seller and Purchaser acknowledge that the
matters relating to the REIT, the initial public offering of REIT securities
(the "IPO"), this Agreement, the price paid to Seller, the identity of Seller
and its principals and the other documents, terms, conditions and information
related thereto (collectively, the "Information") are confidential in nature.
Therefore, Seller and Purchaser covenant and agree to keep the Information
confidential and will not (except as required by applicable law, regulation or
legal process, and only after

                                      -5-
<PAGE>

compliance with the provisions of this Section 2.6), without the other's prior
written consent, disclose any Information in any manner whatsoever; provided,
however, that the Information may be revealed only to key employees, legal
counsel and financial advisors of Purchaser and Seller, each of whom shall be
informed of the confidential nature of the Information and shall agree to act in
accordance with the terms of this Section 2.6. In the event that Seller,
Purchaser or their key employees, legal counsel or financial advisors
(collectively, the "Information Group") are requested pursuant to, or required
by, applicable law, regulation or legal process to disclose any of the
Information, the applicable member of the Information Group will notify
Purchaser or Seller, as applicable, promptly so that one may seek a protective
order or other appropriate remedy or, in its sole discretion, waive compliance
with the terms of this Section 2.6. In the event that no such protective order
or other remedy is obtained, or that Purchaser and Seller waive compliance with
the terms of this Section 2.6, the applicable member of the applicable
Information Group may furnish only that portion of the Information which it is
advised by counsel is legally required and will exercise all reasonable efforts
to obtain reliable assurance that confidential treatment will be accorded the
Information. Seller and Purchaser acknowledge that remedies at law may be
inadequate to protect Purchaser, Seller or the REIT against any actual or
threatened breach of this Section 2.6, and, without prejudice to any other
rights and remedies otherwise available, Seller and Purchaser agree to the
granting of injunctive relief in favor of the REIT and/or Purchaser and/or
Seller without proof of actual damages.

            (c) The obligations of Section 2.6(b) shall not apply to any
Confidential Information which the Purchaser or Seller, as applicable can
demonstrate:

                  (A) is or becomes available to the public through no breach of
this Agreement;

                  (B) was previously known by the receiving party without any
obligation to hold it in confidence;

                  (C) is received from a third party free to disclose such
information without restriction;

                  (D) is independently developed by the receiving party without
the use of Confidential Information of the disclosing party;

                  (E) is approved for release by written authorization of the
disclosing party, but only to the extent of and subject to such conditions as
may be imposed in such written authorization;or

                  (F) Is required in the judgment of counsel to be disclosed in
connection with any stock, equity, debt or other rights offering by Purchaser or
Seller.

      (d) Liquidation Transaction. Seller hereby consents to the Liquidation
Transaction and agrees to the admission of the Liquidating LLC Members as
members in the LLC.

                                      -6-
<PAGE>

            (e) Further Acts. In addition to the acts, instruments and
agreements recited herein and contemplated to be performed, executed and
delivered by Purchaser and Seller, Seller shall perform, execute, and deliver or
cause to be performed, executed, and delivered at the Closing or after the
Closing, any and all further acts, instruments, and agreements and provide such
further assurances as Purchaser may reasonably require at no material cost to
Seller to consummate the transactions contemplated hereunder.

                                  ARTICLE III
                       CONDITIONS PRECEDENT TO THE CLOSING

      3.1 Conditions to Purchaser's Obligations. In addition to any other
conditions set forth in this Agreement, Purchaser's obligation to consummate the
Closing is subject to the timely satisfaction of each and every one of the
conditions and requirements set forth in this Section 3.1, all of which shall be
conditions precedent to Purchaser's obligations under this Agreement.

            (a) Seller's Obligations. Seller shall have performed all
obligations of Seller hereunder which are to be performed prior to Closing, and
shall have delivered or caused to be delivered to Purchaser, all of the
documents and other information required of Seller pursuant to Section 4.2.

            (b) Seller's Representations and Warranties. Seller's
representations and warranties set forth in Section 2.2 shall be true and
correct in all material respects as if made again on the Closing Date, and
Seller shall have executed and delivered to Purchaser at Closing a certificate
to the foregoing effect.

            (c) No Injunction. On the Closing Date, there shall be no effective
injunction, writ, preliminary restraining order or other order issued by a court
of competent jurisdiction restraining or prohibiting the consummation of the
transactions contemplated hereby.

            (d) Completion of IPO. The IPO shall have been completed.

            (e) Liquidation Transaction. The Liquidation Transaction shall have
been consummated.

            (f) Mortgage Loan. Purchaser shall pay off the Mortgage Loan on the
Closing Date.

            (g) Closing. The Closing shall have occurred on or prior to March
31, 2005.

      3.2 Conditions to Seller's Obligations. In addition to any other
conditions set forth in this Agreement, Seller's obligations to consummate the
Closing is subject to the timely satisfaction of each and every one of the
conditions and requirements set forth in this Section 3.2, all of which shall be
conditions precedent to Seller's obligations under this Agreement.

                                      -7-
<PAGE>

            (a) Purchaser's Obligations. Purchaser shall have performed all
obligations of Purchaser hereunder which are to be performed prior to Closing,
and shall have delivered or caused to be delivered to Seller, all of the
documents and other information required of Purchaser pursuant to Section 4.3.

            (b) Purchaser's Representations and Warranties. Purchaser's
representations and warranties set forth in Section 2.1 shall be true and
correct in all material respects as if made again on the Closing Date, and
Purchaser shall have executed and delivered to Seller at Closing a certificate
to the foregoing effect.

            (c) No Injunction. On the Closing Date, there shall be no effective
injunction, writ, preliminary restraining order or other order issued by a court
of competent jurisdiction restraining or prohibiting the consummation of the
transactions contemplated hereby.

            (d) Completion of IPO. The IPO shall have been completed.

            (e) Liquidation Transaction. The Liquidation Transaction shall have
been consummated.

            (f) Mortgage Loan. Purchaser shall pay off the Mortgage Loan on the
Closing Date.

            (g) Closing. The Closing shall have occurred on or prior to March
31, 2005.

                                   ARTICLE IV
                          CLOSING AND CLOSING DOCUMENTS

      4.1 Closing. The consummation and closing (the "Closing") of the
transactions contemplated under this Agreement shall take place at the offices
of Hunton & Williams LLP, Washington, D.C., or such other place as is mutually
agreeable to the parties, on the date of the closing of the IPO (the "Closing
Date"), or as otherwise set by agreement of the parties; provided, however, that
this Agreement shall terminate if Closing does not occur prior to March 31,
2005.

      4.2 Seller's Deliveries. At the Closing, Seller shall deliver the
following to Purchaser in addition to all other items required to be delivered
to Purchaser by Seller:

            (a) Assignment of Membership Interests. Seller shall have executed
and delivered an Assignment, in substantially the form of Exhibit B attached
hereto, granting and conveying to Purchaser good and indefeasible title to the
Membership Interests, free and clear of all liens, encumbrances, security
interests, prior assignments, voting agreements, conditions, restrictions,
claims, and other matters affecting title thereto.

            (b) Authority Documents. Evidence satisfactory to Purchaser that the
person or persons executing the closing documents on behalf of Seller has full
right, power, and authority to do so.

                                      -8-
<PAGE>

            (c) FIRPTA Certificate. An affidavit from Seller certifying pursuant
to Section 1445 of the Internal Revenue Code that Seller is not a foreign
corporation, foreign partnership, foreign trust, foreign estate or foreign
person (as those terms are defined in the Internal Revenue Code and the Income
Tax Regulations promulgated thereunder), in form and substance satisfactory to
Purchaser.

            (d) Certificate of Representations and Warranties. The certificate
required by Section 3.1.

            (e) Books and Records. All books, records, operating reports,
appraisal reports, files and other materials in Seller's possession or control
which are necessary in Purchaser's discretion to maintain continuity of
operation of the Property and the LLC.

            (f) Other Documents. Any other document or instrument reasonably
requested by Purchaser or required hereby.

      4.3 Purchaser's Deliveries. At the Closing, Purchaser shall deliver the
following to Seller:

            (a) Purchase Price. The Purchase Price, as adjusted pursuant to the
terms of this Agreement.

            (b) Authority Documents. Evidence satisfactory to Seller that the
person or persons executing the closing documents on behalf of Purchaser have
full right, power, and authority to do so.

            (c) Certificate of Representations and Warranties. The certificate
required by Section 3.2.

            (d) Other Documents. Any other document or instrument reasonably
requested by Seller or required hereby.

      4.4 Fees and Expenses; Closing Costs. Purchaser shall pay all fees,
expenses and closing costs relating to the transactions contemplated by this
Agreement; provided however, that Seller shall pay its own attorneys' and
consultants' fees and expenses.

      4.5 Adjustments.

            (a) At Closing, Seller shall be credited with Seller's Share of any
cash held by the LLC or by the property manager for the benefit of the LLC as of
the date of Closing.

            (b) All income and expenses with respect to the Membership Interest,
and applicable to the period of time before and after Closing, determined in
accordance with generally accepted accounting principles consistently applied,
shall be allocated between Seller and Purchaser. Seller shall be entitled to
Seller's Share of all income and responsible for Seller's Share of all expenses
of the LLC and the Property for the period of time up to but not including

                                      -9-
<PAGE>

the date of Closing, and Purchaser shall be entitled to all such income and
responsible for all such expenses for the period of time after and including the
date of Closing. Without limiting the generality of the foregoing, the following
items of income and expense shall be prorated at Closing:

                  (i) Rents (including additional rent, pass throughs, etc.).
                  (Rent collections during month of Closing shall be applied
                  first to the current month's rent, then to any past due rents,
                  and then to future (prepaid) rents. At Closing, a
                  reconciliation of pass throughs shall be made based on the
                  property manager's most recent reforecast of operating results
                  for the calendar year. Rent collections following the month of
                  Closing shall be applied first to the current month's rent,
                  then to any past due rents accruing on or after Closing, then
                  to any past due rents accruing before Closing and then to
                  future (prepaid) rents. Purchaser agrees to use reasonable
                  commercial efforts (but shall not be required to commence
                  litigation or eviction proceedings) to collect any past due
                  rents accruing before Closing and to promptly remit to Seller
                  its portion of any such rent collected.)

                  (ii) Real estate and personal property taxes. (If the LLC is
                  in process of prosecuting a property tax appeal when Closing
                  occurs, Purchaser agrees to cause the Company to continue to
                  use the Company's existing attorney or tax appeal consultant
                  until such appeal is completed. Any savings in taxes realized
                  and attorney or consultant fees incurred shall be prorated
                  between Seller and Purchaser based on the relevant tax
                  year(s).)

                  (iii) Utility charges (including but not limited to charges
                  for water, sewer and electricity).

            (c) Seller shall be responsible for Seller's Share of all one time
tenant improvement costs, tenant allowances, broker's fees and commissions and
all other costs and expenses associated with existing leases of the Property;
provided, however, that Purchaser shall be responsible for all tenant
improvement costs, tenant allowances, broker's fees and commissions and other
one time costs and expenses associated with new leases of the Property entered
into after the date of this Agreement with the consent of Purchaser; provided,
further that if there is no Closing under this Agreement, Purchaser shall pay
all one time tenant improvement costs, tenant allowances, broker's fees and
commissions and all other costs and expenses associated for any lease entered
into during the pendency of this Agreement unless the Seller shall have
consented to such lease, which consent shall not be unreasonably withheld,
delayed or conditioned.

            (d) Purchaser shall pay off the Mortgage Loan on the Closing Date.
However, Purchaser shall be solely responsible (and shall not receive any credit
against the Purchase Price) for any prepayment penalties or lender fees paid in
connection with the pay off of the Mortgage Loan.

                                      -10-
<PAGE>

                                   ARTICLE V
                                  MISCELLANEOUS

      5.1 Notices. Any notice provided for by this Agreement and any other
notice, demand, or communication required hereunder shall be in writing and
either delivered in person (including by confirmed facsimile transmission) or
sent by registered or certified mail or overnight courier, return receipt
requested, in a sealed envelope, postage prepaid, and addressed to the party for
which such notice, demand or communication is intended at such party's address
as set forth in this Section. All notices to Purchaser shall be addressed as
follows:

      PURCHASER:

            Columbia Equity LP
            c/o Carr Capital Corporation
            1750 H Street, NW, Suite 500
            Washington, DC  20005
            Telephone: (202) 303-3060
            Facsimile: (202) 303-3078
            Attn: Oliver T. Carr, III

Seller's address for all purposes under this Agreement shall be the following:

      SELLER:

            c/o Ka Po'e Hana LLC
            PMB 249
            1718 M Street, NW
            Washington, DC 20036-4504

Any address or name specified above may be changed by a notice given by the
addressee to the other party. Any notice, demand or other communication shall be
deemed given and effective as of the date of delivery in person or receipt set
forth on the return receipt. The inability to deliver because of changed address
of which no notice was given, or rejection or other refusal to accept any
notice, demand or other communication, shall be deemed to be receipt of the
notice, demand or other communication as of the date of such attempt to deliver
or rejection or refusal to accept.

      5.2 Entire Agreement; Modifications and Waivers; Cumulative Remedies. This
Agreement supersedes any existing letter of intent between the parties,
constitutes the entire agreement among the parties hereto and may not be
modified or amended except by instrument in writing signed by the parties
hereto, and no provisions or conditions may be waived other than by a writing
signed by the party waiving such provisions or conditions. No delay or omission
in the exercise of any right or remedy accruing to Seller or Purchaser upon any
breach under this Agreement shall impair such right or remedy or be construed as
a waiver of any such breach theretofore or thereafter occurring. The waiver by
Seller or Purchaser of any breach of any term,

                                      -11-
<PAGE>

covenant, or condition herein stated shall not be deemed to be a waiver of any
other breach, or of a subsequent breach of the same or any other term, covenant,
or condition herein contained. All rights, powers, options, or remedies afforded
to Seller or Purchaser either hereunder or by law shall be cumulative and not
alternative, and the exercise of one right, power, option, or remedy shall not
bar other rights, powers, options, or remedies allowed herein or by law, unless
expressly provided to the contrary herein.

      5.3 Exhibits. All exhibits referred to in this Agreement and attached
hereto are hereby incorporated in this Agreement by reference.

      5.4 Successors and Assigns. Except as set forth in this Article, this
Agreement may not be assigned by Purchaser or Seller without the prior approval
of the other parties hereto. This Agreement shall be binding upon, and inure to
the benefit of, Seller, Purchaser, and their respective legal representatives,
successors, and permitted assigns.

      5.5 Article Headings. Article headings and article and section numbers are
inserted herein only as a matter of convenience and in no way define, limit, or
prescribe the scope or intent of this Agreement or any part hereof and shall not
be considered in interpreting or construing this Agreement.

      5.6 Governing Law. This Agreement shall be construed and interpreted in
accordance with the laws of the Commonwealth of Virginia, without regard to
conflicts of laws principles.

      5.7 Counterparts. This Agreement may be executed in any number of
counterparts and by any party hereto on a separate counterpart, each of which
when so executed and delivered shall be deemed an original and all of which
taken together shall constitute but one and the same instrument.

      5.8 Survival. All representations and warranties contained in this
Agreement, and all covenants and agreements contained in the Agreement which
contemplate performance after the Closing Date shall survive the Closing.

      5.9 Severability. In case any one or more of the provisions contained in
this Agreement shall for any reason be held to be invalid, illegal, or
unenforceable in any respect, such invalidity, illegality, or unenforceability
shall not affect any other provision hereof, and this Agreement shall be
construed as if such invalid, illegal, or unenforceable provision had never been
contained herein.

      5.10 Attorneys' Fees. Should a party employ an attorney or attorneys to
enforce any of the provisions hereof or to protect its interest in any manner
arising under this Agreement, or to recover damages for breach of this
Agreement, any non-prevailing party in any action pursued in a court of
competent jurisdiction (the finality of which is not legally contested) shall
pay to the prevailing party all reasonable costs, damages, and expenses,
including reasonable attorneys' fees, expended or incurred in connection
therewith.

                                      -12-
<PAGE>

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK.]
                     [SIGNATURES APPEAR ON FOLLOWING PAGES.]

                                      -13-
<PAGE>

         IN WITNESS WHEREOF, this Agreement has been entered into effective as
of the date above first written.

                              SELLER:

                              Kulea, LLC, a Virginia limited liability company
                              By:  Ka Po's Hana LLC, its manager

                              By:               /s/ Joseph R. Rymal
                                  --------------------------------------------
                              Name: Joseph R. Rymal
                              Title: Vice President Investments


                              PURCHASER:

                              Columbia Equity LP, a Virginia limited partnership

                              By: _________________, a __________, its
                                  general partner

                              By:               /s/ Oliver T. Carr, III
                                  ----------------------------------------------
                              Name:
                                    ____________________________________________
                              Title:
                                     ___________________________________________

                                      -14-
<PAGE>

                                    EXHIBIT A

<PAGE>

                                    EXHIBIT B

                                   ASSIGNMENT

_________________________, a __________ ("Assignor"), for good and valuable
consideration paid to the Assignor by _______________________, a
[___________________] ("Assignee"), pursuant to the Share Purchase Agreement
dated as of ____________, 2004, by and between Assignor and Assignee (the
"Agreement") and for other good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, does hereby sell, assign, transfer,
convey and deliver to the Assignee, its successors and assigns, good and
indefeasible title to the Membership Interests, free and clear of all liens,
encumbrances, security interests, prior assignments, voting agreements,
conditions, restrictions, pledges, claims, and other matters affecting title
thereto.

Capitalized terms used but not defined herein shall have the respective meanings
ascribed to them in the Agreement.

IN WITNESS WHEREOF, the parties hereto have caused this Assignment to be signed
by a duly authorized officer this __ day of _____, 2004.

                              ______________________________, a
                              ___________________________

                              By:____________________________________
                              Name:__________________________________
                              Title:_________________________________


<PAGE>

                                    EXHIBIT A
                   PROJECTED SALE DISTRIBUTIONS AS OF 9-23-04

<TABLE>
<S>                            <C>                                              <C>                               <C>
Sales/Contribution Price       15,300,000                                       sales price                         5,300,000
  less Expected indebtedness   10,650,000                                       cash on hand                        1,509,221 (1)
Net Sales proceeds              4,650,000                                       less
                                                                                selling costs
                                                                                unfunded liabilities                 (439,596) (2)
Sales Price                    15,300,000                                       closing prorations due to buyer      (161,720) (3)
Net Sales Proceeds              5,357,905                                       deferred maintenance                 (200,000) (4)
Implied debt & Exp              9,942,095                                       debt balance                      (10,650,000)
                                                                                prepayment penalty                          -  (5)

                                                                                                                    5,357,905
</TABLE>

<TABLE>
<CAPTION>
                                                          NET SALES     CASH FLOW         TOTAL
INVESTOR                      INVESTMENT         %         PROCEEDS   DISTRIBUTIONS   DISTRIBUTIONS
---------------------         -----------    ---------    ---------   -------------   -------------
<S>                           <C>            <C>          <C>         <C>             <C>
Oliver Carr Company               208,311        4.34%      232,533       24,607          257,140
Carr Holding LLC                  208,311        4.34%      232,533       24,607          257,140
Kulea                           3,599,844       75.00%    4,018,429      425,229        4,443,658
Carr Capital/Holuloa              783,326       16.32%      874,410       92,530          966,940
                              -----------    ---------    ---------   ----------      -----------
                                4,799,792      100.00%    5,357,905      566,972        5,924,877
</TABLE>

NOTES:

      (1)Includes cash bal. of as of 8/31/04 plus an expected additional $75,000
            of distributions for Sept., Oct, & Nov.

      (2)Includes remaining leasing costs for Shapiro Bernson and Ahold leases

      (3)Includes security deposits

      (4)Includes estimated cost of parking lot repairs

      (5)Buyer is responsible for any prepayment penalties per the purchase
            contract