EXHIBIT 99.5 OPERATING AGREEMENT

Exhibit 99.5

2233 WISCONSIN AVENUE, LLC

OPERATING AGREEMENT

TABLE OF CONTENTS

TABLE OF CONTENTS
(continued)

TABLE OF CONTENTS
(continued)

2233 WISCONSIN AVENUE, LLC

OPERATING AGREEMENT

     This OPERATING AGREEMENT of 2233 WISCONSIN AVENUE, LLC (the “ Company ”) is made as of September 28, 2006 (this “ Agreement ”), by and among COLUMBIA EQUITY LP, a Virginia limited partnership (“ Columbia ” ), 2233 WISCONSIN AVENUE SPE, INC. , a Virginia corporation (“Corporate Member ”) and AETNA LIFE INSURANCE COMPANY , a Connecticut corporation (“ Aetna ”), as members of the Company (collectively, the “ Members ” and each a “ Member ”), and, in the case of Corporate Member, as the initial Manager (as hereinafter defined) of the Company.

      WHEREAS , the Company was formed as a limited liability company pursuant to the Act (as hereinafter defined) by the filing of a certain Articles of Organization of a Domestic Limited Liability Company with the Virginia State Corporation Commission on or about July 28, 2006, and the Members desire that the business and affairs of the Company are to be governed by this Agreement, subject to the Act; and

      WHEREAS , the Members have identified the Property (as hereinafter defined) as an attractive investment and desire to invest in the Property through the Company.

      NOW, THEREFORE , in consideration of the agreements and obligations set forth herein and for other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Members hereby agree as follows:

ARTICLE 1
DEFINED TERMS

      §1.1 Definitions. Unless the context otherwise requires, capitalized terms used herein shall have the meanings ascribed to them as set forth below:

     “ Accountants ” shall mean such certified public accountants as the Manager shall designate with the Consent of Aetna; provided , in the event the Accountants do not provide service reasonably acceptable to Aetna, Aetna shall have the right, upon thirty (30) days’ prior written notice to Manager (which notice shall provide specifics of unacceptable accounting services), to have the Company replace the Accountants with another certified public accounting firm designated by the Manager with the Consent of Aetna.

     “ Act ” means the Virginia Limited Liability Company Act, Annotated Code of Virginia, §§13.1 - 1000 et seq ., as amended from time to time.

     “ Additional Preferred Contribution ” has the meaning set forth in § 4.2 hereof.

     “ Adjusted Capital Account Deficit ” shall mean, at any time, the then balance in the Capital Account of a Member, after giving effect to the following adjustments:

     (i) credit to such Capital Account any amounts that such Member is deemed obligated to restore as described in the penultimate sentences of Treasury Regulations §1.704-2(g)(1) and Treasury Regulations §1.704-2(i)(5), or any successor provisions; and

     (ii) debit to such Capital Account the items described in Treasury Regulations §§1.704-1(b)(2)(ii)(d)(4), (5) and (6). The foregoing definition of Adjusted Capital Account Deficit is intended to comply with the provisions of §1.704-1(b)(2)(ii)(d) of the Treasury Regulations and shall be interpreted consistently therewith.

     “ Advancing Member ” has the meaning set forth in §4.2 hereof.

     “ Aetna ” shall mean Aetna Life Insurance Company, or its permitted successors or assigns in interest as a Substitute Member.

     “ Affiliate ” means with respect to a specified Person, any Person that directly or indirectly Controls, is Controlled by, or is under common Control with, the specified Person.

     “ Agreement ” means this Agreement, as amended, modified, supplemented or restated from time to time.

     “ Annual Budget ” has the meaning set forth in §11.3(a) hereof.

     “ Asset Management Fee ” shall have the meaning ascribed to such term in Section 6.3(a) hereof.

     “ Asset Value ” means, with respect to any asset, such asset’s adjusted basis for federal income tax purposes, except as follows:

     (i) the initial Asset Value of any asset contributed by a Member to the Company shall be the fair market value of such asset, as agreed to by the contributing Member and the Manager;

     (ii) the Asset Value of all Company assets shall be adjusted to equal their respective fair market values, as determined by the Manager, as of the following times: (a) the contribution of assets to the Company by a new or existing Member as consideration for such Member’s Interest; (b) the distribution by the Company to a Member of more than a de minimis amount of Company assets as consideration for such Member’s Interest; and (c) the liquidation of the Company within the meaning of Treasury Regulations §1.704-1(b)(2)(ii)(g); provided , however, that adjustments pursuant to clauses (a) and (b) of this sentence shall be made only if the Manager reasonably determines that such

adjustments are necessary or appropriate to reflect the relative economic interests of the Members in the Company; and

     (iii) the Asset Value of any Company asset distributed to any Member shall be the fair market value of such asset on the date of distribution (net of the amounts of any liens thereon), as approved by the Manager.

     If the Asset Value of any asset has been determined or adjusted pursuant to Paragraph (i) or Paragraph (ii) above, such Asset Value shall thereafter be adjusted by the Depreciation taken into account with respect to such asset for purposes of computing Profits and Losses.

     “ Bankruptcy ” means the voluntary or involuntary filing (which is not discharged within ninety (90) days) under federal or state bankruptcy or insolvency laws, or assignment for the benefit of creditors, receivership or similar creditor reorganization proceedings.

     “ Business Day ” means any day on which commercial banks in the Commonwealth of Virginia and the District of Columbia are open for the transaction of business.

     “ Buy/Sell Event ” shall mean any event, action or condition which, pursuant to the terms of this Agreement, would permit the initiation of the Buy/Sell Provisions of §6.6.

     “ Capital Account ” means, with respect to any Member, the account maintained for such Member in accordance with the provisions of Article IV hereof.

     “ Capital Contribution ” means with respect to any Member, the aggregate amount of money and the initial Asset Value of any property (other than money) contributed to the Company pursuant to Article IV hereof with respect to such Member’s Interest, excluding Preferred Contributions and Additional Preferred Contributions.

     “ Capital Transaction ” means any financing, refinancing, sale, exchange or any other disposition or transfer of the Property or any part thereof, including, without limitation, (i) a ground lease of any part of the Property (but excluding space leases of any of the Property in the ordinary course of business), (ii) any condemnation or taking by eminent domain of all or any portion of the Property, (iii) any casualty to the Property or any part thereof, or (iv) any loss as a result of a title defect in the Property covered by title insurance.

     “ Capital Transaction Proceeds ” means the net proceeds received by the Company from any Capital Transaction after the payment of (i) all reasonable and customary costs, expenses, charges, fees, including collection expenses and taxes paid by the Company (other than taxes imposed on Members in their individual capacities), and other reasonable and customary expenses related thereto, (ii) any costs of restoration or repair of the Property performed in connection with such Capital Transaction, or any other capital expenditures or other reasonable and customary expenses for which such

proceeds or awards are used, and/or (iii) any mortgage loan, including debt service payments hereunder, or any other debts or liabilities of the Company that are being refinanced, discharged or paid with such proceeds.

     “ Certificate ” means that certain Articles of Organization of a Domestic Limited Liability Company and any and all amendments thereto and restatements thereof filed on behalf of the Company with the Virginia State Corporation Commission.

     “ Closing ” means the effective date of the acquisition of the Property by the Company.

     “ Code ” means the Internal Revenue Code of 1986, as amended from time to time, or any corresponding federal tax statute enacted after the date of this Agreement. A reference to a specific section (§) of the Code refers not only to such specific section, but also to any corresponding provision of any federal tax statute enacted after the date of the Agreement, as such specific section or corresponding provision is in effect on the date of application of the provisions of this Agreement containing such reference.

     “ Columbia ” means Columbia Equity LP, a Virginia limited partnership or its permitted successors or assigns in interest as a Substitute Member.

     “ Company ” shall have the meaning ascribed to such term in the first paragraph of this Agreement.

     “ Consent of Aetna ” means the prior written consent of Aetna as may be required hereunder.

     “ Control ” means the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of a Person, whether through ownership of voting securities, by contract or otherwise.

     “ Corporate Member ” shall mean 2233 Wisconsin Avenue SPE, Inc., a Virginia corporation, or its permitted successors or assigns as a Substitute Member.

     “ Day-to-Day Management ” means the supervision, overseeing and management by Manager of the day-to-day operations of the use, operation, leasing and maintenance of the Property and compliance of the Property with material Requirements, and any sale or other disposition of the Property for which the Consent of Aetna has been given.

     “ Decision Threshold Amount ” shall mean seventy-five thousand dollars ($75,000).

     “ Default ” shall mean the material default of a Member or the Manager in respect of any of such Member’s or such Manager’s obligations hereunder, as applicable, including, without limitation, any failure by Manager to obtain the Consent of Aetna prior to taking any action constituting a Major Decision, which default remains uncured (i) for a period of ten (10) days after receipt by the defaulting Member or Manager as applicable, of notice thereof by the other Member if such default is monetary in nature or

(ii) for a period of thirty (30) days after receipt by the defaulting Member or Manager of notice thereof by the other Member if such default is not monetary in nature, provided , however , that if a default is not monetary in nature and cannot reasonably be cured within such thirty (30) day period, then such defaulting Member or Manager shall not be deemed to be in Default hereunder so long as such Member or Manager shall both commence to cure such default during such thirty (30) day period and thereafter diligently pursue to completion the curing of such default. In addition, the following shall constitute a “Default” hereunder with respect to a Member or the Manager, as applicable: (a) the dissolution or liquidation of such Member or Manager, the Bankruptcy of such Member or Manager or any of its principals, or any other event that results in such Member ceasing to be a Member (other than as expressly provided in this Agreement); (b) such Member becoming subject to any final order of a court of competent jurisdiction requiring such Member to divest itself of all or any portion of its interest in the Company; (c) the failure of Manager to maintain the Company as a “special purpose entity” as provided in §5.4 of this Agreement; (d) the withdrawal or retirement of such Member from the Company in breach of the covenant contained in §10.3; (e) the transfer of all or any part of such Member’s interest in the Company, or any interest therein, in breach of the covenants contained in §5.3 or §10.1 of this Agreement.

     “ Defaulting Member ” means, at any time, a Member which has committed or is the subject of a Default which has not been cured or waived.

     “ Depreciation ” means, for each Fiscal Year or other period, an amount equal to the depreciation, amortization or other cost recovery deduction allowable for federal income tax purposes with respect to an asset for such Fiscal Year or other period; provided, however , that if the Asset Value of an asset differs from its adjusted basis for federal income tax purposes at the beginning of such Fiscal Year or other period, Depreciation shall be an amount that bears the same ratio to such beginning Asset Value as the federal income tax depreciation, amortization or other cost recovery deduction with respect to such asset for such Fiscal Year or other period bears to such beginning adjusted tax basis; and provided further , that if the federal income tax depreciation, amortization or other cost recovery deduction for such Fiscal Year or other period is zero, Depreciation shall be determined with reference to such beginning Asset Value using any reasonable method selected by the Manager.

     “ Electing Member ” has the meaning set forth in §6.6(a) hereof.

     “ First Mortgage ” means the mortgage securing the Mortgage Loan, held by Wells Fargo Bank, N.A., as Trustee for the benefit of Certificate Holders of Commercial Mortgage Pass-Through Certificates Series Wachovia Bank 2003-C-5, or its successors or assigns as holder of the Mortgage Loan.

     “ Fiscal Year ” means the calendar year.

     “ Funding Notice ” has the meaning set forth in § 4.2 hereof.

     “ Ground Lease ” means that certain Amended and Restated Ground Lease dated as of                      , 2006 between Thomas W. Holland, Robert M. Holland, Mary Charlotte Parr and Margaret W. Krull, as “Ground Lessor”, and the Company, as “Ground Lessee”, pursuant to which the Company has leased the Property, and all amendments, modifications, restatements, extensions, renewals, supplements and replacements thereof.

     “ Hazardous Materials ” means (i) asbestos in any form; (ii) urea formaldehyde foam insulation; (iii) polychlorinated biphenyls; (iv) any other “hazardous waste”, as that term is defined by the Resource Conservation and Recovery Act, 42 U.S.C. §6903(5), “hazardous substances”, as that term is defined by the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (“ CERCLA ”), 42 U.S.C. §9601(14), “pollutants” or “contaminants”, as those terms are defined by CERCLA, 42 U.S.C. §9601(33), (v) volatile organic compounds, including oil and petroleum products, or (vi) any other substance, compound or material whose use, storage, manufacture, transportation or disposal is proscribed or conditioned by the documents evidencing or securing the Mortgage Loan or other indebtedness secured by the Property.

     “ Interest ” means a Member’s entire interest as a Member in the Company, including without limitation, such Member’s rights under this Agreement, such Member’s share of the Profits and Losses of the Company and such Member’s rights to receive distributions of Net Cash Flow and the Company’s assets in accordance with the provisions of this Agreement and the Act.

     “ IRR ” means, as to any Member as of any date (an “ IRR Determination Date ”), the rate of return at which, as of the IRR Determination Date: (i) the then present value of all distributions made from time to time with respect to such Member’s Capital Contributions equals, (ii) the then present value of all Capital Contributions made from time to time by such Member. For purposes of the foregoing: (a) present values shall be calculated from the time of the making of each Capital Contribution and based on a monthly accrual at a rate equal to the IRR for which the equation is being solved; (b) a Member’s reinvestment rate shall be assumed to equal the IRR for which the equation is being solved; (c) subject to the provisions of clause (d), all of the present value calculations are to be made as of the date when Capital Contributions were contributed to the Company; (d) all Capital Contributions after the date hereof shall be treated as having been contributed to the Company on the first day of the month during which a Member’s funds were actually delivered (or deemed delivered) to the Company; (e) all distributions shall be treated as if received on the last day of the month in which the distribution was made; (f) the rates of return shall be per annum rates and all amounts shall be calculated on a monthly basis and compounded on a monthly basis on the basis of a 12 month year; and (g) solely for purposes of computing an IRR, Capital Contribution of the Members set forth on Schedule A shall be treated, subject to the provisions of clause (d), as having been made on the date of this Agreement.

     “ Liquidation ” has the meaning set forth in §14.2 hereof.

     “ Major Decision ” shall mean any of the following decisions or actions to be made or taken, as the case may be, that is not provided for in the Annual Budget:

     “ Management Agreement ” shall mean that certain Management Agreement dated as of September 21, 2006 between the Company and Trammel Crow Services, Inc. or such other agreement providing for the management of the Property by Property Manager entered into with the Consent of Aetna.

     “ Manager ” shall mean the Corporate Member, unless and until (a) a successor Manager is designated pursuant to §6.1(d), (b) Corporate Member is removed as Manager pursuant to §6.6(e), or (c) Aetna exercises its right to replace the Corporate Member as Manager pursuant to §6.7, in any of which case “ Manager ” shall mean and refer to such successor or replacement Manager on and after such date.

     “ Member Nonrecourse Deductions ” means an item of loss, expense or deduction attributable to a nonrecourse liability of the Company for which a Member bears the economic risk of loss within the meaning of Treasury Regulations §1.704-2(b)(4).

     “ Members ” means Columbia, the Corporate Member and Aetna collectively, or their respective permitted successors or assigns in interest as a substitute Member.

     “ Membership Percentage ” means, with respect to any Member at any time, its proportionate ownership interest in the Company at such time, expressed as a percentage. The Membership Percentage for each Member is, as of the date of this Agreement, set forth on Schedule A , which shall be updated by Manager from time to time as necessary to reflect any changes in such Membership Percentages in accordance with this Agreement.

     “ Minimum Gain ” means “ partnership minimum gain ”, as that term is defined in Treasury Regulations §1.704-2(d). The amount of Minimum Gain equals the total amount of gain the Company would realize for federal income tax purposes if it disposed of all assets subject to Nonrecourse Debts for no consideration other than full satisfaction thereof.

     “ Mortgage Loan ” means that certain mortgage loan in the original principal amount of $16,500,000.00, made by Suburban Capital Markets, Inc. to Unicorn Wisconsin, LLC (the Company’s predecessor-in-interest as ground lessee of the Property), as assumed by the Company and amended, secured by the First Mortgage.

     “ Mortgage Loan Documents ” means the documents evidencing or securing the Mortgage Loan or executed by the Company for the benefit of the holder of the Mortgage Loan in connection therewith.

     “ Net Cash Flow ” means, with respect to any Fiscal Year or other period of the Company, the net income of the Company, calculated in accordance with generally accepted accounting principles, plus the amount of depreciation and other non-cash items that were deducted for the purpose of calculating net income, minus the amount of capital expenditures, principal payments upon indebtedness for money borrowed and other cash expenditures that were not deducted for the purpose of calculating net income (excluding any repayments of Preferred Contributions or Additional Preferred Contributions or the payment of any returns thereon) and minus amounts deposited for the establishment or replenishment of any Company reserves established and maintained in accordance with the then applicable Annual Budget or required under the terms of the Mortgage Loan.

     “ Non-Defaulting Member ” at any time mean a Member who is not a Defaulting Member at such time.

     “ Non-Discretionary Expenses ” means the following:

     (i) real estate taxes and assessments on the Property;

     (ii) payments required to be made pursuant to the Mortgage Loan and any other mortgage loan secured by the Property and approved by all Members or any other indebtedness of the Company approved by the Members or permitted hereunder, as well as any costs of curing any default under any such mortgage or other indebtedness;

     (iii) utility costs and insurance premiums directly related to the Property;

     (iv) any costs of any alteration, repair or replacement necessary to comply with any Requirements;

     (v) any amount required to be paid by the Company pursuant to any final order, judgment, or decree of any court or governmental body having jurisdiction;

     (vi) any amount required to fulfill any contractual obligation of the Company, including any contracts with any Affiliates of Members; and

any amount required for the safety of tenants, occupants or invitees of the Property or to avoid the suspension of any services necessary to such tenants, occupants or invitees.

     “ Non-Electing Member ” has the meaning set forth in §6.6(a) hereof.

     “ Non-Participating Member ” has the meaning set forth in § 4.2 hereof.

     “ Nonrecourse Debt ” means debt of the Company or any partnership (or other entity treated as a partnership for federal income tax purposes) in which the Company holds an interest, directly or indirectly through other partnerships (or other such entities), as to which no partner or member of the applicable partnership or other entity is personally liable, as determined under §752 of the Code and Treasury Regulations §1.752-1(a)(2).

     “ Nonrecourse Deductions ” has the meaning set forth in Treasury Regulations §1.704-2(c). The amount of Nonrecourse Deductions for a Fiscal Year equals the net increase, if any, in the amount of Company Minimum Gain during the fiscal year, reduced (but not below zero) by the aggregate distributions made during the year of proceeds of a nonrecourse liability that are allocable to an increase in Company Minimum Gain.

     “ Percentage Interest ” means, at any time, (a) in determining the distribution of Net Cash Flow pursuant to §9.1 of this Agreement, Aetna’s Percentage Interest shall be 60%, Columbia’s Percentage Interest shall be 39.5% and Corporate Member’s percentage interest shall be 0.5%; and (b) in determining the distribution of Capital Transaction

Proceeds and any other cash pursuant to §9.2 of this Agreement, as follows: (i) from the date hereof, Aetna 60%, Columbia 39.5% and Corporate Member 0.5%, until such time as all Members have received Capital Transaction Proceeds equal to their respective Capital Contributions, and then (ii) Aetna 60%, Columbia 39.5% and Corporate Member 0.5% until such time as Aetna has received an IRR on its Capital contribution of 10% per annum, and then (iii) Aetna 35%, Columbia 64.5% and Corporate Member 0.5%. For purposes of determining the distribution of Net Cash Flow and the annual returns of the Members in respect of their Capital Contributions, (x) subject to the provisions of clause (y) of this sentence, all of the annual return calculations are to be made as of the date when Capital Contributions were contributed to the Company; and (y) the initial Capital Contributions made by the Members shall be deemed to have been made as of the date of the Closing.

     “ Person ” means any individual, corporation, partnership, limited liability company, joint venture, association, joint stock company, trust (including any beneficiary thereof), unincorporated organization, or government or any agency or political subdivision thereof.

     “ Personal Representative ” means the successor or legal representative (including, without limitation, a guardian, executor, administrator or conservator) of a dead or incompetent Member.

     “ Preferred Contribution ” has the meaning set forth in § 4.2 hereof.

     “ Prime Rate ” means, with respect to any Preferred Contribution or Additional Preferred Contribution the prime rate of interest announced as such (for U.S. money center commercial banks) from time to time in The Wall Street Journal, on the most recent business day preceding the day such Preferred Contribution or Additional Preferred Contribution was made.

     “ Profits ” and “ Losses ” means, for each Fiscal Year an amount equal to the Company’s taxable income or loss for such Fiscal Year, determined in accordance with §703(a) of the Code (but including in taxable income or loss, for this purpose, all items of income, gain, loss or deduction required to be stated separately pursuant to §703(a)(1) of the Code), with the following adjustments:

     (i) any income of the Company exempt from federal income tax and not otherwise taken into account in computing Profits or Losses pursuant to this definition shall be added to such taxable income or loss;

     (ii) any expenditures of the Company described in §705(a)(2)(B) of the Code (or treated as expenditures described in §705(a)(2)(B) of the Code pursuant to Treasury Regulations §1.704-1 (b)(2)(iv)(i)) and not otherwise taken into account in computing Profits or Losses pursuant to the definition shall be subtracted from such taxable income or loss;

     (iii) in the event the Asset Value of any Company asset is adjusted in accordance with Paragraph (ii) or Paragraph (iii) of the definition of “ Asset

Value ” above, the amount of such adjustment shall be taken into account as gain or loss from the disposition of such asset for purposes of computing Profits or Losses;

     (iv) gain or loss resulting from any disposition of any asset of the Company with respect to which gain or loss is recognized for federal income tax purposes shall be computed by reference to the Asset Value of the asset disposed of, notwithstanding that the adjusted tax basis of such asset differs from its Asset Value; and

     (v) in lieu of the depreciation, amortization and other cost recovery deductions taken into account in computing such taxable income or loss, there shall be taken into account Depreciation for such Fiscal Year or other period, computed in accordance with the definition of “ Depreciation ” above; and

     (vi) notwithstanding any other provision hereof, any items which are specially allocated pursuant to Article VIII shall not be taken into account in computing Profit or Losses.

     “ Property ” means the real property and improvements thereon commonly known as Georgetown Plaza, consisting of a five-story office and retail building and parking structure located at 2233 Wisconsin Avenue, N.W., Washington, D.C..

     “ Property Manager ” shall mean Trammel Crow Services, Inc. or other property management company selected by Manager with the consent of Aetna.

     “ Proposed Budget ” has the meaning set forth in §11.3(a) hereof.

     “ Purchase Agreement ” means that certain Agreement for Purchase and Sale, dated December 6, 2005, by and between, Unicorn Wisconsin, LLC and Columbia Equity Trust, Inc., as amended by the First Amendment to Agreement for Purchase and Sale dated as of December 30, 2005, the Second Amendment to Agreement for Purchase and Sale dated as of January 26, 2006, the Third Amendment to Agreement for Purchase and Sale dated as of February 15, 2006, the Fourth Amendment to Agreement for Purchase and Sale dated as of March 1, 2006, the Fifth Amendment to Agreement for Purchase and Sale dated as of March 15, 2006, the Sixth Amendment to Agreement for Purchase and Sale dated as of March 21, 2006, the Seventh Amendment to Agreement for Purchase and Sale dated as of March 31, 2006, the Eighth Amendment to Agreement for Purchase and Sale dated as of April 20, 2006, the Reaffirmation and Ninth Amendment to Agreement for Purchase and Sale, dated as of July 20, 2006 and the Reaffirmation and Tenth Amendment to Agreement for Purchase and Sale, dated as of September 14, 2006, and as assigned to the Company by Assignment and Assumption Agreement of even date herewith by and between Columbia Equity Trust, Inc. and the Company.

     “ Real Estate Operating Company ” shall have the meaning ascribed to such term in Department of Labor Regulation §2510.3-101(e) (29 CFR §2510.3-101(e)).

     “ Recourse Debt ” means debt of the Company or any partnership (or other entity treated as a partnership for federal income tax purposes) in which the Company holds an interest, directly or through other partnerships (or other such entities), as to which a partner or member or any related person bears the economic risk of loss, as determined under §752 of the Code and Treasury Regulations §1.752-1 (a)(1).

     “ Requirements ” shall mean all present and future laws, rules, orders, ordinances, regulations, statutes, requirements, codes and executive orders, of all governmental authorities having jurisdiction over the Property, or the National Board of Fire Underwriters, affecting the maintenance, use or occupation of the Property.

     “ State ” shall mean the Commonwealth of Virginia.

     “ Tax Matters Partner ” has the meaning set forth in §12.1 hereof.

     “ Transfer ” has the meaning set forth in §10.1 hereof.

     “ Treasury Regulations ” means the income tax regulations, including temporary regulations, promulgated under the Code, as such regulations may be amended from time to time (including corresponding provision of succeeding regulations).

      §1.2 Use of Certain Terms . The terms “ approve ”, “ approval ”, or “ authorized ”, as well as any derivations of such terms, when used in reference to any Person, shall refer to the approval or authorization of such Person, as signified in writing from such Person.

ARTICLE 2
FORMATION AND TERM

      §2.1 Formation; Capital Contributions .

          (a) The Company was formed pursuant to the filing of the Certificate pursuant to the provisions of the Act. The Members hereby agree that, effective upon the date of this Agreement, the rights, duties and liabilities of the Members shall be governed by this Agreement, subject to the Act.

          (b) The name and mailing address of each Member and the Capital Contributions to the Company of each Member as of the date hereof are listed on Schedule A attached hereto. The Manager shall update Schedule A from time to time as necessary to accurately reflect the information therein, including, without limitation, to reflect any Capital Contributions after the date hereof, any Transfers of Interests and any admissions of new Members pursuant to Article X hereof. Any reference in this Agreement to Schedule A shall be deemed to be a reference to Schedule A as amended and in effect from time to time.

          (c) Any of Manager or any other officer of the Company, duly authorized by the Manager as an authorized person within the meaning of the Act, shall

execute, deliver and file any and all amendments to the Certificate and any restatements thereof.

      §2.2 Name. The name of the limited liability company formed by the filing of the Certificate and governed by this Agreement is 2233 Wisconsin Avenue, LLC. The business of the Company may be conducted upon compliance with all applicable laws under any other name approved by the Manager and Aetna, provided, such name shall not include “ Aetna ” or any phonetic equivalent thereto.

      §2.3 Term. The term of the Company commenced on the date of the filing of the Certificate with the Virginia State Corporation Commission and shall continue until dissolved in accordance with the provisions of this Agreement.

      §2.4 Registered Agent and Office . The Company’s registered agent and office in the State shall be Colin J. Smith, Watt, Tieder, Hoffar & Fitzgerald, 8405 Greensboro Drive, Suite 100, McLean, VA 22102. At any time, the Manager may approve another registered agent and/or registered office.

      §2.5 Principal Place of Business . The principal place of business of the Company shall be located at 1750 H Street, N.W., Suite 500, Washington, D.C. 20006. At any time, Manager may change the location of the Company’s principal place of business, provided Manager provides all other Members with prior written notice of such change.

ARTICLE 3
PURPOSE AND POWERS OF THE COMPANY

      §3.1 Purpose . Notwithstanding any provision hereof to the contrary, the following shall govern: The nature of the business and of the purposes to be conducted and promoted by the Company, is to engage solely in the following activities:

          (a) To acquire the Property pursuant to the Purchase Agreement;

          (b) To own, hold, sell, assign, transfer, operate, lease, mortgage, pledge and otherwise deal with the Property;

          (c) To exercise all powers enumerated in the Act necessary or convenient to the conduct, promotion or attainment of the business or purposes otherwise set forth herein. The Company shall not carry on or engage in any other activity.

      §3.2 Powers of the Company .

          (a) The Company shall have the power and authority to take any and all actions necessary, appropriate, proper, advisable, convenient or incidental to or for the furtherance of the purposes set forth in §3.1, including, but not limited to, the power:

     (i) to conduct its business, carry on its operations and have and exercise the powers granted to a limited liability company by the Act in any state,

territory, district or possession of the United States, or in any foreign country that may be necessary, convenient or incidental to the accomplishment of the purpose of the Company;

     (ii) to acquire by purchase, lease, contribution of property or otherwise, own, hold, operate, maintain, finance, improve, lease, sell, convey, mortgage, transfer, demolish or dispose of any real or personal property that may be necessary, convenient or incidental to the accomplishment or the purposes of the Company;

     (iii) to enter into, perform and carry out contracts of any kind, including, without limitation, the Purchase Agreement, contracts with any Member, Manager or any officer of the Company or any Affiliate thereof, or any agent of the Company necessary to, in connection with, convenient to, or incidental to the accomplishment of the purpose of the Company;

     (iv) to purchase, take, receive, subscribe for or otherwise acquire, own, hold, vote, use, employ, sell, mortgage, lend, pledge or otherwise dispose of, and otherwise use and deal in and with, shares or other interests in or obligations of domestic or foreign corporations, associations, general or limited partnerships (including, without limitation, the power to be admitted as a partner thereof and to exercise the rights and perform the duties created thereby), trusts, limited liability companies (including, without limitation, the power to be admitted as a member or appointed as a manager thereof and to exercise the rights and perform the duties created thereby), or direct or indirect obligations of the United States or of any foreign government, or of any state, territory, governmental district or municipality or instrumentality or any of them;

     (v) to lend money for any proper purpose, to invest and reinvest its funds, and to take and hold real and personal property for the payment of funds so loaned or invested;

     (vi) to sue and be sued, complain and defend, and participate in administrative or other proceedings, in its name;

     (vii) to appoint employees and agents of the Company, and define their duties and fix their compensation;

     (viii) to indemnify any Person in accordance with the Act and to obtain any and all types of insurance;

     (ix) to cease its activities and cancel its Certificate;

     (x) to negotiate, enter into, renegotiate, extend, renew, terminate, modify, amend, waive, execute, acknowledge or take any other action with respect to any lease, contract or security agreement in respect of any assets of the Company;

     (xi) to borrow money and issue evidences of indebtedness, and to secure the same by a mortgage, pledge or other lien on the assets of the Company;

     (xii) to pay, collect, compromise, litigate, arbitrate or otherwise adjust or settle any and all claims or demands of or against the Company; and

     (xiii) to make, execute, acknowledge and file any and all documents or instruments necessary, convenient or incidental to the accomplishment of the purpose of the Company.

          (b) The Manager may authorize any Person (including, without limitation, any Member) to enter into and perform any document, instrument or agreement on behalf of, and in the name of the Company.

          (c) Notwithstanding the provisions of this Article III, Article IV or any other provisions of this Agreement, all Major Decisions shall require the prior approval of all Non-Defaulting Members. All Members hereby approve the Company assuming the Mortgage Loan and executing the Mortgage Loan Documents and hereby authorize the Manager to execute and deliver the Mortgage Loan Documents for and on behalf of the Company.

          (d) Notwithstanding any provision hereof to the contrary, the following shall govern: The Company shall only incur indebtedness in an amount necessary to acquire, operate and maintain the Property. For so long as the First Mortgage exists on any portion of the Property, the Company shall not incur, assume, or guaranty any other indebtedness. The Company shall not consolidate or merge with or into any other entity or convey or transfer its properties and assets substantially as an entirety to any entity. For so long as the First Mortgage exists on any portion of the Property, the Company will not voluntarily commence a case with respect to itself, as debtor, under the Federal Bankruptcy Code or any similar federal or state statute without the unanimous consent of all of the Members. For so long as the First Mortgage exists on any portion of the Property, no material amendment to this Agreement may be made without first obtaining approval of the mortgagees holding first mortgages on any portion of the Property.

ARTICLE 4
CAPITAL CONTRIBUTIONS, CAPITAL ACCOUNTS AND PREFERRED CONTRIBUTIONS

      §4.1 Initial Capital Contributions . As of the date of this Agreement, the Capital Contributions made by each Member to the Company are set forth opposite its name on Schedule A hereto, such Capital Contributions to be made not later than the date of the Closing.

      §4.2 Additional Funding Request . If Manager determines, in its reasonable discretion, that additional funds are required for the operation of the Company or the Property, then Manager shall, if and only to the extent permitted under the Mortgage Loan, first attempt to arrange for the Company to borrow such funds from third party

lenders at market rates. If it is not possible to borrow funds from third party lenders, Manager shall give written notice (the “ Funding Notice ”) thereof to all of the Members setting forth (i) the amount of additional funds so required, (ii) the proposed application of such funds, and (iii) when any such additional funds are to be funded (which funding date shall not be less than sixty (60) days following the delivery of the notice pursuant to this Section; provided that the time for such funding shall be determined at Manager’s discretion in the event of an emergency). Upon receipt of a Funding Notice, any Member shall have the right, but not the obligation, to fund to the Company an amount (a “ Preferred Contribution ”) equal to the product obtained by multiplying its Membership Percentage by the additional funds required. A Member’s failure to fund a Preferred Contribution shall not be considered to be a Default hereunder. A Member shall be entitled to a return on any Preferred Contribution made by such Member at a rate equal to the Prime Rate plus two percent (2%) per annum, and such Preferred Contributions and such return shall be repaid as hereinafter provided. If any Member (the “ Non-Participating Member ”) chooses not to make a Preferred Contribution to the Company within the time period set forth in the applicable Funding Notice, then the other Members, or any of them (the “ Advancing Member(s) ”) may make such additional Preferred Contributions (“ Additional Preferred Contributions ”) to the Company which in the aggregate are equal to the amount of the Preferred Contribution which the Non-Participating Member elected not to make, in such proportion (in the event there is more than one (1) Advancing Member) between them as their Membership Percentages bear inter se . A Member shall be entitled to a return on any Additional Preferred Contribution made by such Member at a rate equal to the Prime Rate plus four percent (4%) per annum, and such Additional Preferred Contribution and return shall be repaid as hereinafter provided.

      §4.3 Payment of Preferred Contributions and Additional Preferred Contributions . Manager shall duly record among the Company’s books and records the date and amount of each Preferred Contribution and Additional Preferred Contribution made to the Company, and the name of each Member making the same. Preferred Contributions shall be payable from the first available Net Cash Flow. Additional Preferred Contributions shall be repayable to the Advancing Member solely from (i) payments received by the Non-Participating Member on account of Preferred Contributions made by the Non-Participating Member to the Company, and (ii) the Non-Participating Member’s allocable share of the first available Net Cash Flow after payments with respect to any Preferred Contributions. In the event that distributions of Net Cash Flow have been insufficient to fully repay any Preferred Contributions or Additional Preferred Contributions, then any remaining balance due (including any accrued return) shall be repaid solely from distributions of Company assets pursuant to Section 9.2 below.

      §4.4 Limitations Pertaining to Capital Contributions .

          (a)  Return of Capital . Except as otherwise provided in this Agreement, no Capital Contributions or any money or other property shall be withdrawn from or paid by the Company unless such withdrawal or payment is approved by the unanimous consent of the Members. Under circumstances requiring a return of any Capital Contributions, no Member shall have the right to receive property other than cash.

          (b)  No Third Party Rights . Nothing in this Agreement is intended or will be deemed to benefit any creditor of the Company, and no creditor or the Company will be entitled to require