Document:

EX-10.126

THIS WARRANT AND THE COMMON STOCK ISSUABLE UPON EXERCISE HEREOF HAVE NOT BEEN REGISTERED UNDER
THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”), OR ANY OTHER SECURITIES LAWS AND MAY NOT BE
OFFERED FOR SALE, SOLD, TRANSFERRED, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF (1) AN EFFECTIVE
REGISTRATION STATEMENT COVERING SUCH SECURITIES UNDER THE ACT AND ANY OTHER APPLICABLE SECURITIES
LAWS, OR (2) AN OPINION OF COUNSEL REASONABLY SATISFACTORY TO THE CORPORATION THAT SUCH
REGISTRATION IS NOT REQUIRED.

HALO TECHNOLOGY HOLDINGS, INC.

WARRANT TO PURCHASE _______ SHARES OF

COMMON STOCK, PAR VALUE $0.00001 PER SHARE

Date      Warrant No.      —     

For value received, HALO TECHNOLOGY HOLDINGS, INC., a Nevada corporation (the
“Corporation”), hereby certifies that      , or its registered transferees, successors or
assigns (each person or entity holding all or part of this Warrant being referred to as a
“Holder”), is the registered holder of warrants (the “Warrants”) to subscribe for
and purchase      (     ) shares (as adjusted pursuant to Section 3 hereof, the
“Warrant Shares”) of the fully paid and nonassessable common stock, par value $0.00001 per
share (the “Common Stock”), of the Corporation, at a purchase price per share initially
equal to ONE DOLLAR AND TWENTY-FIVE CENTS ($1.25) (the “Warrant Price”) on or before, 5:00
P.M., Eastern Time, on      (the “Expiration Date”), subject to the provisions and
upon the terms and conditions hereinafter set forth; provided, however, that in the
event that any portion of this Warrant is unexercised as of the Expiration Date, the terms of
Section 1(b) below shall apply. As used in this Warrant, the term “Business Day”
means any day other than a Saturday or Sunday on which commercial banks located in New York, New
York are open for the general transaction of business. This Warrant has been issued in connection
with the holder’s investment in the Corporation’s Common Stock pursuant to that certain
Subscription Agreement between the holder and the Company of even date herewith.

1. Exercise.

(a) Method of Exercise; Payment; Issuance of New Warrant.

(i) Subject to the provisions hereof, the Holder may exercise this Warrant,
in whole or in part and from time to time, by the surrender of this Warrant (with the Notice
of Exercise attached hereto as Appendix A duly executed) at the principal office of
the Corporation, or such other office or agency of the Corporation as it may reasonably
designate by written notice to the Holder, during normal business hours on any Business Day,
and the payment by the Holder by cash, certified check payable to the Corporation or wire
transfer of immediately available funds to an account designated to the exercising Holder by
the Corporation of an amount equal to the then applicable Warrant Price multiplied by the
number of Warrant Shares then being purchased, or in the event of a cashless exercise
pursuant to Section 1(c) below, with the Net Issue Election Notice attached hereto
as Appendix B duly executed and completed. On the date on which the Holder shall
have satisfied in full the Holder’s obligations set forth herein regarding an exercise of
this Warrant (provided such date is prior to the Expiration Date), the Holder (or such other
person or persons as directed by the Holder, subject to compliance with applicable
securities laws) shall be treated for all purposes as the holder of record of such Warrant
Shares as of the close of business on such date.

(ii) In the event of any exercise of the rights represented by this Warrant,
certificates for the whole number of shares of Common Stock so purchased shall be delivered
to the Holder (or such other person or persons as directed by the Holder, subject to
compliance with applicable securities laws) as promptly as is reasonably practicable (but
not later than three (3) Business Days) after such exercise at the Corporation’s expense,
and, unless this Warrant has been fully exercised, a new Warrant representing the whole
number of Warrant Shares, if any, with respect to which this Warrant shall not then have
been exercised shall also be issued to the Holder as soon as reasonably practicable
thereafter (but not later than three (3) Business Days) after such exercise.

(b) Automatic Exercise. If any portion of this Warrant remains unexercised as of
the Expiration Date and the Fair Market Value of one share of Common Stock as of the Expiration
Date is greater than the applicable Warrant Price as of the Expiration Date, then this Warrant
shall be deemed to have been exercised automatically immediately prior to the close of business on
the Expiration Date (or, in the event that the Expiration Date is not a Business Day, the
immediately preceding Business Day) (the “Automatic Exercise Date”) in the manner provided
in Section 1(c) below, and the Holder (or such other person or persons as directed by the
Holder, subject to compliance with applicable securities laws) shall be treated for all purposes as
the holder of record of such Warrant Shares as of the close of business on such Automatic Exercise
Date. This Warrant shall be deemed to be surrendered to the Corporation on the Automatic Exercise
Date by virtue of this Section 1(b) without any action by the Holder. As promptly as is
reasonably practicable on or after the Automatic Exercise Date, but in no event prior to the date
on which this Warrant is surrendered to the Corporation at the principal office of the Corporation,
or such other office or agency of the Corporation as it may reasonably designate by written notice
to the Holder, during normal business hours on any Business Day, the Corporation at its expense
shall issue and deliver to the Holder (or such other person or persons as directed by the Holder,
subject to compliance with applicable securities laws) a certificate or certificates for the number
of Warrant Shares issuable upon such exercise, in accordance with Section 1(c).

(c) Cashless Right to Convert Warrant into Common Stock. Notwithstanding any
provision herein to the contrary, if as of the date of exercise of all or a part of this Warrant,
the Fair Market Value for one share of Common Stock is greater than the Warrant Price, then in lieu
of exercising this Warrant for cash, the Holder may elect to receive, without the payment by the
Holder of the Warrant Price, Warrant Shares equal to the value of this Warrant or any portion
hereof by the surrender of this Warrant (or such portion of this Warrant being so exercised)
together with the Net Issue Election Notice annexed hereto as Appendix B duly executed and
completed, at the office of the Corporation, or such other office or agency of the Corporation as
it may reasonably designate by written notice to the Holder, during normal business hours on any
Business Day. Thereupon, the Corporation shall issue to the Holder such number of fully paid,
validly issued and nonassessable Warrant Shares, as is computed using the following formula:

X= Y(A-B)

A

where

X = the number of shares of Common Stock to be issued to the Holder (or such other person or
persons as directed by the Holder, subject to compliance with all applicable laws) upon such
exercise of the rights under this Section 1(c)

Y = the total number of shares of Common Stock covered by this Warrant which the Holder has
surrendered for cashless exercise

A = the “Fair Market Value” of one share of Common Stock on the date that the Holder delivers
the Net Issue Election Notice to the Corporation as provided herein

B = the Warrant Price in effect under this Warrant on the date that the Holder delivers the
Net Issue Election Notice to the Corporation as provided herein

The “Fair Market Value” of a share of Common Stock as of a particular date (the
“Valuation Date”) shall mean the following:

(i) if the Common Stock is then listed on a national securities exchange, the
average closing sale price of one share of Common Stock on such exchange over the ten (10)
trading days ending on the last trading day prior to the Valuation Date; provided that if
such stock has not traded in the ten (10) consecutive trading days prior to the Valuation
Date, the Fair Market Value shall be the average closing price of one share of Common Stock
in the most recent ten (10) trading days during which the Common Stock has traded prior to
the Valuation Date;

(ii) if the Common Stock is then included in The Nasdaq Stock Market, Inc.
(“Nasdaq”), the average closing sale price of one share of Common Stock on Nasdaq
over the ten (10) trading days ending on the last trading day prior to the Valuation Date
or, if no closing sale price is available for any of such ten (10) trading days, the closing
sale price for such day shall be determined as the average of the high bid and the low ask
price quoted on Nasdaq as of the end of such trading day; provided that if the Common Stock
has not traded in the ten (10) consecutive trading days prior to the Valuation Date, the
Fair Market Value shall be the average closing price of one share of Common Stock in the
most recent ten (10) trading days during which the Common Stock has traded prior to the
Valuation Date;

(iii) If the Common Stock is then included in the Over-the-Counter Bulletin
Board, the average closing sale price of one share of Common Stock on the Over-the-Counter
Bulletin Board over the ten (10) trading days ending on the last trading day prior to the
Valuation Date or, if no closing sale price is available for any of such ten (10) trading
days, the closing sale price for such day shall be determined as the average of the high bid
and the low ask price quoted on the Over-the-Counter Bulletin Board as of the end of such
trading day; provided that if the Common Stock has not traded in the ten (10) consecutive
trading days prior to the Valuation Date, the Fair Market Value shall be the average closing
price of one share of Common Stock in the most recent ten (10) trading days during which the
Common Stock has traded prior to the Valuation Date;

(iv) if the Common Stock is then included in the “pink sheets”, the average
closing sale price of one share of Common Stock on the “pink sheets” over the ten (10)
trading days ending on the last trading day prior to the Valuation Date or, if no closing
sale price is available for any of such ten (10) trading days, the closing sale price for
such day shall be determined as the average of the high bid and the low ask price quoted on
the “pink sheets” as of the end of such trading day; provided that if the Common Stock has
not traded in the ten (10) consecutive trading days prior to the Valuation Date, the Fair
Market Value shall be the average closing price of one share of Common Stock in the most
recent ten (10) trading days during which the Common Stock has traded prior to the Valuation
Date; or

(v) if the Common Stock is not then listed on a national securities exchange
or quoted on Nasdaq or the Over-the-Counter Bulletin Board or the “pink sheets”, the Fair
Market Value of one share of Common Stock as of the Valuation Date shall be determined in
good faith by the Board of Directors of the Corporation (the “Board”).

2. Reservation of Shares; Stock Fully Paid; Listing. The Corporation shall
keep reserved a sufficient number of shares of the authorized and unissued shares of Common Stock
to provide for the exercise of the rights of purchase represented by this Warrant in compliance
with its terms. All Warrant Shares issued upon exercise of this Warrant shall be, at the time of
delivery of the certificates for such Warrant Shares upon payment in full of the Warrant Price
therefor in accordance with the terms of this Warrant (or proper exercise of the cashless exercise
rights contained in Section 1(c) hereof), duly authorized, validly issued, fully paid and
non-assessable shares of Common Stock of the Corporation. The Corporation shall during all times
prior to the Expiration Date when the shares of Common Stock issuable upon the exercise of this
Warrant are authorized for listing or quotation on any national securities exchange, Nasdaq (or the
Over-the-Counter Bulletin Board or the “pink sheets”, as the case may be), keep the shares of
Common Stock issuable upon the exercise of this Warrant authorized for listing or quotation on such
national securities exchange, Nasdaq (or the Over-the-Counter Bulletin Board or the “pink sheets”,
as the case may be).

3. Adjustments and Distributions.

3.1 If the Corporation shall, while this Warrant is outstanding, issue or sell shares of its
Common Stock or “Common Stock Equivalents” (as defined below) without consideration
or at a price per share or “Net Consideration Per Share” (as defined below)
less than the Warrant Price in effect immediately prior to such issuance or sale, then in each such
case the Warrant Price then in effect at such time, except as hereinafter provided, shall be
lowered so as to be equal to the Net Consideration Per Share.

(a) Common Stock Equivalents.

	 	(i)	 	General. For the purposes of this Warrant, the
issuance of any warrants, options, subscription or purchase rights with
respect to shares of Common Stock and the issuance of any securities
(including, without limitation, securities evidencing indebtedness)
convertible into or exchangeable for shares of Common Stock and the
issuance of any warrants, options, subscription or purchase rights with
respect to such convertible or exchangeable securities (collectively,
“Common Stock Equivalents”), shall be deemed an issuance of
Common Stock. Any obligation, agreement or undertaking to issue Common
Stock Equivalents at any time in the future shall be deemed to be an
issuance at the time such obligation, agreement or undertaking is made
or arises. No adjustment of the Warrant Price shall be made under this
Warrant upon the issuance of any shares of Common Stock which are
issued pursuant to the exercise, conversion or exchange of any Common
Stock Equivalents.

	 	(ii)	 	Adjustments for Adjustment, Cancellation or
Expiration of Common Stock Equivalents. Should the Net Consideration
Per Share of any such Common Stock Equivalents be decreased from time
to time other than as a result of the application of anti-dilution
provisions substantially similar to the provisions of this Warrant,
then, upon the effectiveness of each such change, the Warrant Price
will be that which would have been obtained (1) had the adjustments
made upon the issuance of such Common Stock Equivalents been made upon
the basis of the new Net Consideration Per Share of such securities,
and (2) had the adjustments made to the Warrant Price since the date of
issuance of such Common Stock Equivalents been made to such Warrant
Price as adjusted pursuant to clause (1) above. Any adjustment of the
Warrant Price which relates to any Common Stock Equivalent shall be
disregarded if, as, and when such Common Stock Equivalent expires or is
canceled without being exercised, or is repurchased by the Corporation
at a price per share at or less than the original purchase price, so
that the Warrant Price effective immediately upon such cancellation or
expiration shall be equal to the Warrant Price that would have been in
effect (1) had the expired or canceled Common Stock Equivalent not been
issued, and (2) had the adjustments made to the Warrant Price since the
date of issuance of such Common Stock Equivalents been made to the
Warrant Price which would have been in effect had the expired or
canceled Common Stock Equivalent not been issued.

(b) Net Consideration Per Share. For purposes of this Warrant, the “Net
Consideration Per Share” which shall be receivable by the Corporation for any
Common Stock issued upon the exercise or conversion of any Common Stock Equivalents shall be
determined as follows:

	 	(i)	 	The “Net Consideration Per Share” shall
mean the amount equal to the total amount of consideration, if any,
received by the Corporation for the issuance of such Common Stock
Equivalents, plus the minimum amount of consideration, if any, payable
to the Corporation upon exercise, or conversion or exchange thereof,
divided by the maximum aggregate number of shares of Common Stock
(without regard to any provision contained therein providing for a
subsequent adjustment to such number) that would be issued if all such
Common Stock Equivalents were exercised, exchanged or converted.

	 	(ii)	 	The “Net Consideration Per Share” which shall
be receivable by the Corporation shall be determined in each instance
as of the date of issuance of Common Stock Equivalents without giving
effect to any possible future upward price adjustments or rate
adjustments which may be applicable with respect to such Common Stock
Equivalents.

(c) Stock Dividends for Holders of Capital Stock Other Than Common Stock. In the
event that the Corporation shall make or issue (otherwise than to holders of Common Stock), or
shall fix a record date for the determination of holders of any capital stock of the Corporation
other than holders of Common Stock entitled to receive, a dividend or other distribution payable in
Common Stock or securities of the Corporation convertible into or otherwise exchangeable for shares
of Common Stock of the Corporation, then such Common Stock or other securities issued in payment of
such dividend shall be deemed to have been issued for their fair market value as is reasonably
determined in good faith by the Board of Directors of the Corporation.

(d) Consideration Other than Cash. For purposes of this Warrant, if a part or all of
the consideration received by the Corporation in connection with the issuance of shares of Common
Stock or the issuance of any of the securities described in this Warrant consists of property other
than cash, such consideration shall be deemed to have a fair market value as is reasonably
determined in good faith by the Board of Directors of the Corporation.

(e) Exceptions to Anti-Dilution Adjustments. This Section 3.1 shall not apply (A)
under any of the circumstances which would constitute an Extraordinary Common Stock Event (as
described below) (such circumstances being accounted for pursuant to Section 3.2 hereof), (B) to
the issuance of Common Stock upon the conversion of the Corporation’s Series C Preferred Stock,
Series B Preferred Stock or Series B-2 Preferred Stock, (C) to the issuance of the Series C
Preferred Stock and the warrants (including this Warrant) issued in connection therewith, (D) upon
the exercise of (x) this Warrant, (y) any warrants issued in connection with the issuance of the
Series C Preferred Stock or any Initial Warrants or Additional Warrants issued pursuant to a
certain Senior Note and Warrant Purchase Agreement, dated as of January 31, 2005, by and among the
Corporation and the Purchasers signatory thereto or other warrants or options to purchase shares of
Common Stock or (z) the warrants issued to Fortress Credit Corp. in connection with the
Corporation’s $50 million senior credit agreement, (E) the issuance of any convertible debt or
convertible equity in connection with the Corporation’s acquisition of five portfolio companies
from Platinum Equity LLC as described in the Corporation’s Current Report on Form 8-K filed with
the Securities and Exchange Commission on September 16, 2005, or the exercise or conversion of any
such debt or equity securities, (F) issuance of any convertible debt or convertible equity as
described in the Corporation’s Current Report on Form 8-K filed with the Securities and Exchange
Commission on January 18, 2006, or the exercise or conversion of any such debt or equity securities
or any dect or equity securities for which such securities are exchanged or (G) other securities
convertible into shares of Common Stock, outstanding prior to the original issue date of this
Warrant. Further, the adjustments described in this Section 3.1 shall not apply with respect to
the issuance or sale of shares of Common Stock, or the grant of options exercisable therefor,
issued or issuable after the original issue date of this Warrant to:

	 	(i)	 	directors, officers, employees and consultants
of the Corporation or any subsidiary pursuant to any qualified or
non-qualified stock option plan or agreement, stock purchase plan or
agreement, stock restriction agreement, employee stock ownership plan,
consultant equity compensation plan or arrangement approved by the
Board of Directors or an authorized committee thereof, including any
repurchase or stock restriction agreement, or such other options,
issuances, arrangements, agreements or plans intended principally as a
means of providing compensation for employment or services and approved
by the Board of Directors;

	 	(ii)	 	capital stock, or options or warrants to
purchase capital stock, issued to financial institutions or lessors in
connection with commercial credit arrangements, equipment financings,
commercial property lease transactions or similar transactions;

	 	(iii)	 	capital stock, or warrants or options to
purchase capital stock, issued in connection with bona fide
acquisitions, mergers or similar transactions, the terms of which are
approved by the Board of Directors of the Corporation; and

	 	(iv)	 	capital stock issued or issuable to an entity
as a component of any business relationship with such entity for the
purpose of (A) joint venture, technology licensing or development
activities, (B) distribution, supply or manufacture of the
Corporation’s products or services or (C) any other arrangements
involving corporate partners that are primarily for purposes other than
raising capital, the terms of which business relationship with such
entity are approved by the Board of Directors.

(f) No Fractional Adjustments. No adjustment of the Warrant Price shall be made in an
amount less than one cent per share, provided that any adjustments which are not required to be
made by reason of this sentence shall be carried forward and shall be either taken into account in
any subsequent adjustment made prior to three years from the date of the event giving rise to the
adjustment being carried forward and prior to exercise, or shall be made at the end of three years
from the date of the event giving rise to the adjustment being carried forward.

(g) No Increased Warrant Price. Notwithstanding any other provisions of this Section
3, except to the limited extent provided for in Sections 3.1(a)(ii), no adjustment of the Warrant
Price pursuant to this Section 3 shall have the effect of increasing the Warrant Price above the
Warrant Price in effect immediately prior to such adjustment.

3.2 Adjustment Upon Extraordinary Common Stock Event. Upon the happening of an
Extraordinary Common Stock Event (as hereinafter defined), the Warrant Price shall, simultaneously
with the happening of such Extraordinary Common Stock Event, be adjusted by multiplying such
Warrant Price by a fraction, the numerator of which shall be the number of shares of Common Stock
outstanding immediately prior to such Extraordinary Common Stock Event and the denominator of which
shall be the number of shares of Common Stock outstanding immediately after such Extraordinary
Common Stock Event, and the product so obtained shall thereafter be the Warrant Price which, as so
adjusted, shall be readjusted in the same manner upon the happening of any successive Extraordinary
Common Stock Event or Events.

An “Extraordinary Common Stock Event” shall mean (i) the issue of additional shares of Common
Stock as a dividend or other distribution on outstanding shares of Common Stock, (ii) a subdivision
of outstanding shares of Common Stock into a greater number of shares of Common Stock, or (iii) a
combination or reverse stock split of outstanding shares of Common Stock into a smaller number of
shares of the Common Stock.

3.3 Adjustment Upon Certain Dividends. In the event the Corporation shall make or
issue, or shall fix a record date for the determination of holders of Common Stock entitled to
receive, a dividend or other distribution with respect to the Common Stock payable in (i)
securities of the Corporation other than shares of Common Stock, or (ii) other
assets (excluding cash dividends or distributions), then and in each such event provision shall be
made so that the Holder shall receive upon exercise of this Warrant in addition to the number of
shares of Common Stock receivable thereupon, the number of securities or such other assets of the
Corporation which they would have received had this Warrant been exercised immediately prior to
such event.

3.4 Adjustment Upon Capital Reorganization or Reclassification. If the Common Stock
shall be changed into the same or different number of shares of any other class or classes of
capital stock, whether by capital reorganization, recapitalization, reclassification or otherwise
(other than an Extraordinary Common Stock Event provided for in Section 3.2, a dividend or other
distribution provided for in Section 3.3, or a merger or other transaction provided for in Section
3.5), then and in each such event, the Holder shall have the right thereafter to receive, upon
exercise of this Warrant, in lieu of the number of shares of Common Stock which the Holder would
otherwise have been entitled to receive, the kind and amount of shares of capital stock and other
securities and property receivable upon such reorganization, recapitalization, reclassification or
other change by the holders of the number of shares of Common Stock for which this Warrant could
have been exercised immediately prior to such reorganization, recapitalization, reclassification or
change, all subject to further adjustment as provided herein.

3.5 Adjustment for Merger or Reorganization, etc.

(a) In case of any consolidation or merger of the Corporation with or into another corporation
or the sale of all or substantially all of the assets of the Corporation to another corporation:
if the surviving entity shall consent in writing to the following provisions, then this Warrant
shall thereafter be exercisable for the kind and amount of shares of stock or other securities or
property to which a holder of the number of shares of Common Stock of the Corporation deliverable
upon exercise of this Warrant would have been entitled upon such consolidation, merger or sale;
and, in such case, appropriate adjustment (as determined in good faith by the Board of Directors)
shall be made in the application of the provisions in this Section 3 with respect to the rights and
interest thereafter of the Holder of this Warrant, to the end that the provisions set forth in this
Section 3 (including provisions with respect to changes in and other adjustments of the Warrant
Price) shall thereafter be applicable, as nearly as reasonably possible, in relation to any shares
of stock or other property thereafter deliverable upon the exercise of this Warrant.

(b) The provision for such rights on each of this Warrant shall be a condition precedent to
the consummation by the Corporation of any such transaction.

3.6 Certificate as to Adjustments; Notice by Corporation. In each case of an
adjustment or readjustment of the Warrant Price, the Corporation at its expense will furnish the
Holder with a certificate prepared by the Treasurer or Chief Financial Officer of the Corporation,
showing such adjustment or readjustment, and stating in detail the facts upon which such adjustment
or readjustment is based.

3.7 Further Adjustments. In the event that, as a result of an adjustment made
pursuant to this Section 3, the Holder shall become entitled to receive any shares of capital stock
of the Corporation other than shares of Common Stock, the number of such other shares so receivable
upon exercise of this Warrant shall be subject thereafter to adjustment from time to time in a
manner and on terms as nearly equivalent as practicable to the provisions with respect to the
Warrant Shares contained in this Warrant.

3.8 Adjustment of Number of Shares. Upon each adjustment in the Warrant Price
pursuant to this Section 3, the number of Warrant Shares purchasable hereunder shall be adjusted,
to the nearest whole share, to the product obtained by multiplying the number of Warrant Shares
purchasable immediately prior to such adjustment by a fraction, (i) the numerator of which shall be
the Warrant Price immediately prior to such adjustment, and (ii) the denominator of which shall be
the Warrant Price immediately thereafter.

4. Transfer Taxes. The Corporation will pay any documentary stamp taxes attributable
to the initial issuance of Warrant Shares issuable upon the exercise of the Warrant;
provided, however, that the Corporation shall not be required to pay any tax or
taxes which may be payable in respect of any transfer involved in the issuance or delivery of any
certificates for Warrant Shares in a name other than that of the registered holder of this Warrant
in respect of which such shares are issued, and in such case, the Corporation shall not be required
to issue or deliver any certificate for Warrant Shares or any Warrant until the person requesting
the same has paid to the Corporation the amount of such tax or has established to the Corporation’s
reasonable satisfaction that such tax has been paid.

5. Mutilated or Missing Warrants. In case this Warrant shall be mutilated, lost,
stolen, or destroyed, the Corporation shall issue in exchange and substitution of and upon
cancellation of the mutilated Warrant, or in lieu of and substitution for the Warrant lost, stolen
or destroyed, a new Warrant of like tenor and for the purchase of a like number of Warrant Shares,
but only upon receipt of evidence reasonably satisfactory to the Corporation of such loss, theft or
destruction of the Warrant, and with respect to a lost, stolen or destroyed Warrant, reasonable and
customary indemnity or bond with respect thereto, if requested by the Corporation.

6. Fractional Shares. No fractional shares of Common Stock shall be issued in
connection with any exercise or cashless exercise hereunder, and in lieu of any such fractional
shares the Corporation shall make a cash payment therefor to the Holder (or such other person or
persons as directed by the Holder, subject to compliance with all applicable laws) based on the
Fair Market Value of a share of Common Stock on the date of exercise or cashless exercise of this
Warrant.

7. Compliance with Securities Act and Legends. The Holder, by acceptance hereof,
agrees that it will not offer, sell or otherwise dispose of this Warrant, or any shares of Common
Stock to be issued upon exercise hereof except under circumstances which will not result in a
violation of the Securities Act of 1933, as amended, or the rules and regulations promulgated
thereunder, as amended (the “1933 Act”), or any state’s securities laws. All shares of
Common Stock issued upon exercise of this Warrant (unless registered under the 1933 Act) shall be
stamped or imprinted with a legend as follows:

THIS SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN
REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED (THE “ACT”),
OR ANY OTHER SECURITIES LAWS AND MAY NOT BE OFFERED FOR SALE, SOLD,
TRANSFERRED, PLEDGED OR HYPOTHECATED IN THE ABSENCE OF (1) AN
EFFECTIVE REGISTRATION STATEMENT COVERING THESE SECURITIES UNDER
THE ACT AND ANY OTHER APPLICABLE SECURITIES LAWS, OR (2) AN OPINION
OF COUNSEL REASONABLY SATISFACTORY TO THE CORPORATION THAT SUCH
REGISTRATION IS NOT REQUIRED.

8. Rights as a Stockholder. Except as expressly provided in this Warrant, no Holder,
as such, shall be entitled to vote or receive dividends or be deemed the holder of Common Stock or
any other securities of the Corporation which may at any time be issuable on the exercise hereof
for any purpose, nor shall anything contained herein be construed to confer upon the Holder, as
such, any of the rights of a stockholder of the Corporation or any right to vote for the election
of the directors or upon any matter submitted to stockholders at any meeting thereof, or to receive
notice of meetings, or to receive dividends or subscription rights or otherwise, until this Warrant
shall have been exercised and the Warrant Shares purchasable upon the exercise hereof shall have
become deliverable, as provided herein.

9. Modification and Waiver. This Warrant and any provision hereof shall not be
changed, waived, discharged or terminated except by an instrument in writing signed by the
Corporation and the then current Holder, and such change, waiver, discharge or termination shall be
binding on any future Holder, provided, however, that no such changes shall be
applicable to the other warrants issued pursuant to the Notes described in the Subscription
Agreement unless the holders thereof expressly agree thereto in writing.

10. Notices. Unless otherwise provided, any notice required or permitted under this
Warrant shall be given in accordance with the terms of the Subscription Agreement.

11. Descriptive Headings. The descriptive headings contained in this Warrant are
inserted for convenience only and do not constitute a part of this Warrant.

12. Governing Law. The validity, interpretation and performance of this Warrant shall
be governed by, and construed in accordance with, the laws of the State of New York applicable to
contracts made and to be performed entirely within such State, regardless of the law that might be
applied under principles of conflicts of law.

13. Acceptance. Receipt and execution of this Warrant by the Holder hereof shall
constitute acceptance of and agreement to the foregoing terms and conditions.

14. Identity of Transfer Agent. The Transfer Agent for the Common Stock is Pacific
Stock Transfer Company. Upon the appointment of any subsequent transfer agent for the Common Stock
or other shares of the Corporation’s capital stock issuable upon the exercise of the rights of
purchase represented by this Warrant, the Corporation will mail to the Holder a statement setting
forth the name and address of such transfer agent.

15. No Impairment of Rights. The Corporation will not, by amendment of its
Certificate of Incorporation or through any other voluntary action, avoid or seek to avoid the
observance or performance of any of the terms of this Warrant, but will at all times in good faith
assist in the carrying out of all such terms and in the taking of all such action as may be
necessary or appropriate in order to protect the rights of the holder of this Warrant against
material impairment.

16. Assignment. Subject to the terms hereof and compliance with applicable federal
and state securities laws, this Warrant may be transferred by the Holder with respect to any or all
of the Warrant Shares then purchasable hereunder. Upon surrender of this Warrant to the
Corporation, together with a properly endorsed notice of transfer (an “Assignment Form”),
for transfer of this Warrant in its entirety by the Holder, the Corporation shall issue a new
warrant of the same denomination to the designated transferee. Upon surrender of this Warrant to
the Corporation, together with a properly endorsed Assignment Form, by the Holder for transfer with
respect to a portion of the Warrant Shares then purchasable hereunder, the Corporation shall issue
a new warrant to the designated transferee, in such denomination as shall be requested by the
Holder hereof, and shall issue to such Holder a new warrant covering the number of Warrant Shares
in respect of which this Warrant shall not have been transferred. In addition to, and not in
limitation of, the foregoing, a Holder that is a corporation, a partnership or a limited liability
company, may distribute any portion of this Warrant to its respective shareholders, partners or
members. Unless and until the provisions for assignment set forth herein have been fully complied
with, the Corporation may treat the last registered Holder as the absolute owner of this Warrant
for all purposes, notwithstanding any notice to the contrary.

17. Limitation on Exercise. Notwithstanding anything to the contrary contained
herein, the number of shares of Common Stock that may be acquired by the Holder upon any exercise
of this Warrant (or otherwise in respect hereof) shall be limited to the extent necessary to insure
that, following such exercise (or other issuance), the total number of shares of Common Stock then
beneficially owned by such Holder and its Affiliates and any other Persons whose beneficial
ownership of Common Stock would be aggregated with the Holder’s for purposes of Section 13(d) of
the Exchange Act, does not exceed 9.99% of the total number of issued and outstanding shares of
Common Stock (including for such purpose the shares of Common Stock issuable upon such exercise).
For such purposes, beneficial ownership shall be determined in accordance with Section 13(d) of the
Exchange Act and the rules and regulations promulgated thereunder. Each delivery of an Exercise
Notice hereunder will constitute a representation by the Holder that it has evaluated the
limitation set forth in this paragraph and determined that issuance of the full number of Warrant
Shares requested in such Exercise Notice is permitted under this paragraph. This provision shall
not restrict the number of shares of Common Stock which a Holder may receive or beneficially own in
order to determine the amount of securities or other consideration that such Holder may receive in
the event of a merger or other business combination or reclassification involving the Corporation
as contemplated in Section 3 of this Warrant. By written notice to the Corporation, the Holder may
waive the provisions of this Section but any such waiver will not be effective until the 61st day
after such notice is delivered to the Corporation.

[Remainder of Page Left Intentionally Blank]

IN WITNESS WHEREOF, the Corporation and the Holder have caused this Warrant to be
executed on their behalf by one of their officers thereunto duly authorized.

HALO TECHNOLOGY HOLDINGS, INC.

By:

Name:

Title:

APPENDIX A

NOTICE OF EXERCISE

To: HALO TECHNOLOGY HOLDINGS, INC.

1. The undersigned hereby irrevocably elects to purchase [     ] shares of Common Stock of HALO
TECHNOLOGY HOLDINGS, INC. pursuant to the terms of the attached Warrant, and tenders herewith
payment of the purchase price of such shares in full, by [cash, certified check/wire transfer, or
surrender of the originally executed Warrant] [select the applicable method of payment].

2. Please issue a certificate or certificates representing said shares in the name of the
undersigned or in such other name or names as are specified below:

     

     

(Name)

     

(Address)

     

(Signature)

     

(Date)

3. Please issue a new Warrant of equivalent form and tenor for the unexercised portion of the
attached Warrant in the name of the undersigned or in such other name as is specified below:

     

Date:      

(Warrantholder)      

Name: (Print)      

By:     

APPENDIX B

Net Issue Election Notice

To: HALO TECHNOLOGY HOLDINGS, INC.

Date:[     ]

The undersigned hereby elects under Section 1(c) of this Warrant to surrender the
right to purchase [     ] shares of Common Stock pursuant to this Warrant and hereby
requests the issuance of [     ] shares of Common Stock. The certificate(s) for the shares
issuable upon such net issue election shall be issued in the name of the undersigned or as
otherwise indicated below.

     

Signature

     

Name for Registration

     

Mailing AddressEX-10.1

AGREEMENT OF PURCHASE AND SALE

THIS AGREEMENT OF PURCHASE AND SALE (“Agreement”) is made and entered into as of the
27th day of July, 2006 (the “Effective Date”), by and between STAFFORD COMMERCE CENTER,
L.L.C., a Virginia limited liability company (“Seller”), and COLUMBIA EQUITY TRUST, INC., a
Maryland corporation, or its permitted assigns (collectively, “Purchaser”).

R E C I T A L S:

A. Seller is the fee simple owner of that certain real property located in Stafford County,
Virginia consisting of certain improvements (including a two-story office building) known by street
address 25 Center Street, Stafford, Virginia, containing approximately 37,052 rentable square feet
in the aggregate and approximately 2.78 acres of land, inclusive of the required on-site parking
facilities, containing approximately 148 parking spaces, for such improvements pursuant to
applicable local law, such real property being more particularly described on Exhibit A
attached hereto; and all right, title and interest of Seller, if any, that is appurtenant to the
real property described on Exhibit A in and to the following: any land lying in the bed of
any existing, dedicated street, road or alley, all strips and gores adjoining thereto and all
appurtenances, rights, easements, rights-of-way, covenants, tenements, hereditaments and other
rights incident thereto, including, without limitation, any right or option to acquire or benefit
from any future easement or right-of-way to the extent that such rights and interests may benefit
such real property (collectively, the “Land”), together with all improvements situated thereon and
all right, title and interest of Seller in and to all other improvements, driveways,
landscaping, paving, walkways, plumbing and heating pipes and fixtures situated thereon that they
may benefit such improvements, situated thereon and/or used in connection therewith to the extent
that they may benefit such improvements (collectively, the “Improvements”), together with all of
Seller’s right, title and interest in and to the Leases identified on Exhibit B attached
hereto (the “Leases”), together with, to the extent assignable, any contract rights other than the
Leases, any escrow or security deposits, utility agreements, guarantees (if any), licenses,
approvals, amounts held in reserve by the holder of the Existing Indebtedness (defined below) with
respect to the Improvements; certificates, certificates of occupancy, plans and specifications,
logos, permits, warranties or other rights related to the development of, construction of,
ownership or, or use and operation of, the real property (all such items being collectively
referred to as the “Intangibles”), and all furniture, fixtures and equipment and other items of
personal property owned by Seller and located in or on the real property (collectively, the
“Personalty”) (the Land and Improvements, together with the Intangibles, Leases and
Personalty, being hereinafter sometimes referred to collectively as the “Property”); and

B. Purchaser desires to acquire the Property, and Seller desires to sell the Property, all
pursuant to the following terms.

NOW, THEREFORE, for and in consideration of the premises and mutual covenants and agreements
herein contained, and for other good and valuable consideration, the receipt and sufficiency of
which are hereby acknowledged, the parties hereto agree as follows:

1. Purchase and Sale. Purchaser agrees to acquire the Property and Seller agrees to sell
the Property (including without limitation its interests in the Leases), pursuant to the terms and
conditions set forth herein.

2. Purchase Price, Method of Payment, Deposit and Closing Escrow.

2.1 Purchase Price. The purchase price for the Property (including without
limitation Seller’s interests in the Leases as aforesaid) shall be Seven Million Five Hundred Two
Thousand Five Hundred Sixty-seven and Zero/100 Dollars ($7,502,567.00) (the “Purchase Price”).

2.2 Method of Payment of Purchase Price. The Purchase Price shall be payable by
Purchaser as follows: (i) Purchaser shall, at Purchaser’s option, assume or pay off the
outstanding principal and interest owed as of the Closing Date (hereinafter defined) by Seller to
Archon Financial, L.P., a Delaware limited partnership, or its assigns (the “Lender”) and secured
by the Property, as more particularly described in Section 3.20 below (the “Existing
Indebtedness”), and (ii) the balance after application toward the Purchase Price of the outstanding
principal and interest due on the Existing Indebtedness as of the Closing Date which is assumed or
paid off by Purchaser, as applicable, as described in (i) above, will be paid by wire transfer of
immediately available funds, of which the Deposit shall be a part, subject to such prorations and
adjustments as are set forth hereinafter.

2.3 Deposit. Within three (3) Business Days (hereinafter defined) following the
Effective Date, Purchaser shall deposit with Commercial Title Group, Inc., located at 8605 Westwood
Center Drive, Suite 200, Vienna, Virginia 22182 (“Escrow Agent”) in cash, One Hundred Twenty-five
Thousand Dollars ($125,000) (the “Initial Deposit”). If Purchaser elects to proceed with this
Agreement beyond the expiration of the Inspection Period (as defined in Article 4 below), no later
than three (3) Business Days after the expiration of the Inspection Period, the Purchaser shall
deliver to the Escrow Agent the additional sum of One Hundred Twenty Five Thousand Dollars
($125,000) in immediately available funds (the “Additional Deposit”). The Deposit shall be held by
the Escrow Agent in an interest bearing escrow account under Purchaser’s tax identification number
and shall be released or applied in accordance with the terms of this Agreement. The Initial
Deposit and the Additional Deposit, together with all interest earned thereon, are collectively
hereinafter referred to as the “Deposit.” The Escrow Agent shall not be liable for any acts or
omissions at any time unless caused by the gross negligence or willful malfeasance of the Escrow
Agent with respect to the escrow established herein. If a dispute arises between the parties as to
the disposition of the Deposit, the Escrow Agent shall: (i) hold the Deposit until the Escrow
Agent has received releases signed by all parties to the transaction authorizing disposition of the
Deposit, or (ii) hold the Deposit until such time as one of the parties to the transaction files
suit and the court in which the suit is filed orders the disbursement of the Deposit, or (iii)
deliver such Deposit into the court by filing an Interpleader Action. In the event of any
litigation between Seller and Purchaser concerning the Deposit, Escrow Agent’s sole responsibility
may be satisfied, at Escrow Agent’s option, by delivering the Deposit into the court in which such
litigation is pending, and Purchaser and Seller agree that upon deliverance of such Deposit into
court, neither Purchaser nor Seller shall have any further right, claim, demand, or action against
the Escrow Agent. In the event any dispute arises under this Agreement between Seller and
Purchaser resulting in the Escrow Agent being made a party to any litigation, Seller and Purchaser,
jointly and severally, shall indemnify the Escrow Agent for all costs, and reasonable attorneys’
fees and legal expenses incurred by the Escrow Agent as a result thereof, provided that such
litigation does not result in a judgment against the Escrow Agent for acting improperly under this
Agreement.

3. Seller’s Representations and Warranties. In order to induce Purchaser to enter into
this Agreement and to purchase the Property, Seller makes the following representations and
warranties, each of which being true and correct in all material respects as of the date hereof and
each of which shall be true and correct in all material respects on the Closing Date.

3.1 Organization and Authority. Seller has full power and authority to enter into
this Agreement, to sell the Property to Purchaser and to otherwise perform its obligations
hereunder. Seller further represents to Purchaser that the execution, delivery and performance of
this Agreement, the fulfillment of and compliance with the terms and provisions hereof and the due
consummation of the transactions contemplated hereby have been duly and validly authorized and
approved by all requisite organizational action, all of which are in full force and effect. The
sale of the Property pursuant to this Agreement (and the consummation of the transactions
contemplated herein) shall not violate any law, ordinance, judgment, decree or order to which
Seller or the Property is subject. Seller is not a “foreign person” as that term is defined by
Section 1445 of the Internal Revenue Code of 1986, as amended. All Related Documents executed by
Seller at the Closing (hereinafter defined) will be duly authorized, executed, and delivered by
Seller, are or at the Closing will be legal, valid, and binding obligations of Seller, are
sufficient to convey title, and do not violate any provisions of any agreement to which Seller is a
party or to which it is subject. The term “Related Documents” shall mean any document or
instrument executed and/or delivered by Seller in connection with or pursuant to the Closing of the
transaction contemplated by this Agreement including, without limitation, the Deed (hereinafter
defined), bill of sale, Lease Assignment and Assumption Agreement (hereinafter defined), Loan
Assumption Documents (hereinafter defined), assignment and assumption of contracts, and the FIRPTA
Certificate (hereinafter defined).

3.2 Encroachments. To Seller’s knowledge, no part of the Improvements encroaches on
any other property, and no Improvements violate any setback requirements. To Seller’s knowledge,
no structures of any kind encroach on the Property.

3.3 Ownership. Seller is the sole, fee simple owner of the Property, free and clear
of liens and encumbrances other than the Permitted Exceptions (defined below) and the liens
securing the Existing Indebtedness which shall be assumed or paid off by Purchaser as of the
Closing Date.

3.4 Oral Agreements. No oral agreement has been entered into with any person or
entity relating to or connected with the ownership, construction, use, operation, maintenance or
condition of the Property which would be binding upon Purchaser at or subsequent to the Closing.

3.5 Insurance. Seller has not received any written notice from any insurance company
which has issued a policy with respect to the Property requesting performance of any structural or
other repairs or alterations to any of the Property which has not been complied with. Seller has
not received from any insurance company presently insuring the Property any notice of cancellation
of any policy or of a material increase in the current premium of any policy. Seller agrees to
keep present coverages in full force and effect, and to pay the premiums thereon, until the date of
Closing.

3.6 Building Documents. To the extent not previously provided or made available to
Purchaser, Seller shall make available to Purchaser within the two (2) day period from and after
the date hereof, for Purchaser’s inspection and photocopying at Seller’s place of business, copies
of all documents, instruments, reports, analyses, surveys, inspections and other information in
Seller’s possession and relating to the Land and/or the condition or construction of the
Improvements and/or the presence of any Hazardous Substances (as herein defined) in or around the
Property, together with copies in Seller’s possession of any and all plans, operating statements,
rent rolls, Service Contracts (hereinafter defined), engineering or architectural studies or
reports and soil or environmental studies or reports; copies in Seller’s possession of any and all
agreements, permits (including use and occupancy certificates and building permits) and approvals
which the Seller has with any governmental authority pertaining to the Property; copies of the
Seller’s existing title policy and all surveys; plats; engineering, mechanical, and architectural
data in Seller’s possession relating to the Property, including if available “as-built” surveys and
“as-built” site plans (including the current, approved site plan) relating to the Property; copies
of all warranties and guaranties of every type in Seller’s possession with respect to the Property;
a copy of Seller’s certificate of insurance evidencing insurance coverage on the Property; and a
copy of most recent real estate tax bill/assessment for the Property (collectively the “Building
Documents”).

3.7 Hazardous Wastes. With respect to the Property (including, without limitation,
the soil and ground water underneath the Improvements), no summons, citation, directive, notice or
complaint issued by the United States Environmental Protection Agency or other federal, state or
local government authority has been received by Seller, its employees or to Seller’s knowledge, its
agents, concerning any alleged violations of any environmental laws and regulations or any
investigation or request for information relating to the handling, packaging, transportation,
treatment, storage or disposal of Hazardous Substances on-site or when transported off-site. To
Seller’s knowledge, the Property is in compliance with all laws, regulations, orders, decrees and
agreements relating to Hazardous Substances and there are no Hazardous Substances on, at or under
the Property as of the date hereof. The term “Hazardous Substances” has the meaning set forth in
the Comprehensive Environmental Response, Compensation and Liability Act of 1980, as amended (42
U.S.C. § 9601 et seq.), and all regulations thereunder. For the purposes of this
Agreement, the term Hazardous Substances also includes radon, petroleum and petroleum products and
asbestos and asbestos products.

3.8 Condemnation. No taking by power of eminent domain or condemnation proceeding has
been instituted or, to Seller’s knowledge, threatened for the permanent or temporary taking or
condemnation of all or any portion of the Property.

3.9 Litigation. There is no pending or, to Seller’s knowledge, threatened,
litigation, proceeding or investigation relating to the Property, Seller’s title thereto, Seller’s
right to sell the Property or the zoning or use of the Property.

3.10 Compliance; Notice of Violations. Seller has received no written notice of any
violation of any law, rule, regulation, order, requirement, code, ordinance, statute or regulation
issued by any government agency, board, commission, authority or other government entity, or any
insurance board of underwriters, or of any action in any court or in any government or
administrative body on account thereof, against or affecting the zoning, use, development,
maintenance, condition or operation of the Property or any part thereof.

3.11 Commitments. Seller has not made, and prior to Closing hereunder shall not make,
any commitments to any government authority or agency, utility company, or to any other
organization, group or person relating to the Property that would impose on Purchaser or the
Property (or any future owner thereof) the obligation to make on or after the Closing any
contributions of money, dedication of land or grants of easements, rights-of-way or other things,
or to construct, install or maintain any improvements, public or private, on or off the Property.

3.12 Liens. No labor has been performed or materials furnished at the request or
direction of Seller that could result in a materialman’s or mechanic’s lien filed against the
Property except as shall be fully paid or released prior to Closing. All real estate taxes on the
Property which have become due and payable prior to Closing have been or will be paid by Closing.

3.13 Leases. There are no leases, license agreements or other occupancy agreements
for the Property binding upon the Purchaser or its successors other than the Leases described on
the schedule of leases attached hereto as Exhibit B. The copies of the Leases delivered to
Purchaser by or on behalf of Seller prior to the execution of this Agreement are true, accurate and
complete in all material respects as of the date hereof, are in full force and effect and none of
the Leases has been further modified, amended or extended. None of the Leases shall be further
extended, modified or amended prior to Closing without the Purchaser’s consent, which shall not be
unreasonably withheld, conditioned or delayed. Neither landlord nor, to Seller’s knowledge any of
the tenants, is in default under the Leases, and there are no other obligations of the landlord
pertaining to the Property except as expressly set forth in the Leases. To the knowledge of
Seller, no controversy, claim, dispute or disagreement exists between the parties to any of the
Leases, and no event has occurred which, with the giving of notice or the passage of time, or both,
would constitute a default under any of the Leases. The Leases are all in full force and effect.
Neither the tenants under the Leases (the “Tenants”) nor any other person, firm or corporation has
any right, option or agreement to purchase the Property, including, but not limited to, purchase
options or rights of first refusal to purchase the Property or any portion thereof. The security
deposits for the Leases are listed on Exhibit B and there are no security deposits or other
deposits other than those described on Exhibit B. There are no brokerage, leasing or other
commissions payable with respect to the Leases as of the date hereof, and at Closing, there shall
be no such commissions payable, whether with respect to the present terms thereunder or any
renewals. Except for the funding of moving expenses offered to Garrett Development Corporation in
connection with its First Amendment to Deed of Lease dated April, 2006 (the costs of such moving
expenses are a Seller obligation that will be credited to Purchaser at Closing), there are no
unperformed requirements under the Leases for the Seller to perform or fund the performance of any
tenant build-out or improvement work.

3.14 Service Contracts. At Closing, there shall be no service, maintenance, supply,
management, leasing contracts or other agreements (“Service Contracts”) except for those Service
Contracts shown on Exhibit C attached hereto and made a part hereof that Purchaser does not
elect to have terminated by providing Seller with a written notice prior to the expiration of the
Inspection Period. In the event that Purchaser provides Seller with a written notice prior to the
expiration of the Inspection Period to terminate all or some of the Service Contracts, Seller shall
ensure the termination of such Service Contracts effective as of the Closing Date. Seller is not
in default under any of the Service Contracts and to its knowledge no other parties to any of the
Service Contracts are in default thereunder. Seller will cause the Management Agreement for the
Property between the Seller and Garrett Development Corporation and any listing or leasing
agreement for the Property to be cancelled effective as of the Closing Date. The copies of the
Service Contracts delivered to Purchaser by or on behalf of Seller prior to execution of this
Agreement are true, accurate and complete in all material respects as of the date hereof, are in
full force and effect and none of them has been further modified, amended or extended.

3.15 Assessments. To Seller’s knowledge, there are no assessments for public
improvements or repairs made or pending against the Property (or any component thereof) which
remain unpaid, including, without limitation, those for construction of sewer, water, gas and
electric lines and mains, streets, roads, sidewalks and curbs and, to Seller’s knowledge, none has
been proposed. Seller has provided Purchaser a true and complete copy of the most recent real
property tax bills for the Property and true and complete copies of bills for any and all public
space rentals, vault rentals and any other public rentals or taxes relating to the use or ownership
of the Property (and all components thereof). Seller shall promptly deliver to Purchaser a true and
complete copy of any new real property tax assessment received for any component of the Property.

3.16 No Actions. Seller shall not knowingly cause or permit by its agents or
employees any action to be taken which would cause any of the representations or warranties
contained or incorporated in this Agreement to be untrue as of the Closing Date. Seller agrees to
notify Purchaser promptly in writing of any event or condition of which Seller becomes aware which
occurs prior to Closing hereunder and which causes a material change in the truth of any of the
representations or warranties contained herein.

3.17 Employees. Seller has not entered into any management contracts, employment
contracts or labor union contracts and has not established any retirement, health insurance,
vacation, pension, profit sharing or other benefit plans relating to the operation or maintenance
of the Property (or any component thereof) for which Purchaser shall have any liability or
obligation. Neither Seller nor its management agent has any employees at the Property (or any
component thereof), other than at-will employees who shall remain the responsibility of Seller or
its management agent and as to whom Purchaser shall have no liability or obligation whatsoever. As
of the Closing Date, there shall be no employees working at the Property (or any component
thereof). Seller shall have paid or caused to be paid to all employees of the Seller or its
management agent all salary and any other payments which shall be payable on account of each such
employee for such period through Closing Date.

3.18 USTs. To the best of Seller’s knowledge, there are no underground storage tanks
located on the Property. Seller has not removed, or caused to be removed, any underground storage
tanks from the Property (although one overground storage tank was removed by Seller at the time of
development of the Property and/or the Related Properties) and, to the best of Seller’s knowledge,
no underground storage tanks were removed from the Property before Seller acquired title to the
Property.

3.19 No Termination of Utilities. Seller has not received any written notice of the
termination or impairment of the furnishing of services to the Property or any component thereof of
water, sewer, gas (if any), electric, telephone, drainage and other such utility services.

3.20 Existing Indebtedness. The documents described on Exhibit D hereto and
made a part hereof (the “Loan Documents” and the funds disbursed thereunder, the “Loan”), are the
only documents or agreements relating to the Existing Indebtedness to which Purchaser will be bound
after the Closing upon an assumption by Purchaser of the Loan. There are no amendments or
modifications (written, oral, by course of conduct or otherwise) to the Loan Documents other than
as described on Exhibit D.

The original principal amount of the Loan to Seller under the Loan Documents was
$3,517,000.00. The current amount of principal outstanding under the Loan Documents is
$3,164,830.34. The annual rate of interest throughout the remaining term of the Loan is 7.31%.
All payments required to be made under the Loan Documents to date have been made and will be made
as of Closing. There are no other fees, expenses or other amounts due to Lender as of the date
hereof (other than transfer or assumption fees which may be imposed after the date of execution of
this Agreement in connection with the transfer of the Existing Indebtedness to Purchaser or
prepayment fees payable in connection with a prepayment of the Loan, which fees shall be payable by
Purchaser in accordance with Section 4.5 below).

Neither Seller nor, to the best of Seller’s knowledge, Lender is in default under the Loan
Documents. There are no other obligations of the Seller to the Lender except as set forth in
writing in the Loan Documents. No controversy, claim, dispute or disagreement exists between the
parties to the Loan Documents. No event has occurred which, with the giving of notice or the
passage of time, or both, would constitute a default under any of the Loan Documents. The Loan
Documents are in full force and effect. There are no reserves held by Lender except as set forth
on Exhibit D.

The Loan Documents shall not be further extended, modified or amended prior to Closing.

There is no pending or, to Seller’s knowledge, threatened, litigation, proceeding or
investigation relating to the Loan Documents.

3.21 No Other Agreements. Without in any way limiting the generality of the foregoing
representation, Seller further represents and warrants to Purchaser that no understanding,
agreement (either express or implied), or reasonable expectancy of agreement with respect to sale
or other transfer of the Property exists between Seller and any third party.

3.22 Completeness and Accuracy. The documents delivered by Seller to Purchaser
pursuant to Section 3.6 above and the other provisions of this Agreement are the material documents
in the possession of Seller or its representative and agents relating to the Property and used by
Seller in its operation of the Property. The representations and warranties contained in this
Agreement do not contain any material untrue statement of fact and do not omit any statement of
fact necessary to make the information herein or therein not materially misleading.

3.23 Absence of Bankruptcy. Neither Seller nor, to the best of Seller’s knowledge,
any member or manager of Seller has commenced (within the meaning of any Bankruptcy Law) a
voluntary case, consented to the entry of an order for relief against it in an involuntary case, or
consented to the appointment of a custodian of it or for all or any substantial part of its
property, nor has a court of competent jurisdiction entered an order or decree under any Bankruptcy
Law that is for relief against Seller or any member or manager of Seller in any involuntary case or
appoints a custodian of Seller or any member or manager of Seller or for all or any substantial
part of its or their property.

3.24 Zoning. There are no outstanding zoning proffers applicable to the Property or
any part thereof. Except for a bond for storm water management in the amount of $13,543 which
Seller has been working to remove (the “Storm Water Bond”), all public site improvements required
to be performed in connection with the development of the Improvements have been completed and any
bond posted to secure the performance of such public site improvements has been released. Seller
accepts responsibility for causing the removal of the Storm Water Bond, will use reasonable efforts
to cause its removal prior to Closing and will indemnify and hold Seller harmless from any cost or
expense related thereto. In the event that Seller is unable to release the Storm Water Bond by
Closing, Seller shall be obligated to release same within ninety (90) days after Closing and shall
fully indemnify Purchaser from any liability therefore.

3.25 Independence of Property. The Property is an independent unit which does not now
rely, and on the Closing Date will not rely, on any facilities (other than the facilities of public
utility and water companies and of access from the public roads) located on any property not
included in the Property (i) to fulfill any legal requirements, (ii) for structural support, or
(iii) for the furnishing to the Improvements of any essential building systems or utilities,
including electrical, plumbing, mechanical and heating, ventilating and air conditioning systems.
No building or other improvement not included in any part of the Property relies on any part of the
Property to fulfill any legal requirements or for structural support or the furnishing to such
building or improvement of any essential building systems or utilities. Notwithstanding the
foregoing, Purchaser acknowledges the obligations set forth in the Declaration (as defined in
Article 8 herein), including without limitation the cross-parking easements described in Section
3.8.

3.26 Utilities. All water, sewer, gas, electricity and other utilities required for
the use, occupancy, operation and maintenance of the Improvements are connected thereto and in
service, are adequate to serve the normal operation of the Property, are supplied directly to the
Property by facilities of public utilities, and the cost of installation and connection of such
utilities has been fully paid. All public utilities required for the operation of the Property
enter the Property through lands as to which valid public or private easements exist that will
inure to the benefit of Purchaser.

The representations and warranties of Seller set forth in this Article 3 shall survive Closing
for a period of one (1) year. No claims for a breach of any representation or warranty of Seller
shall be actionable or payable unless written notice containing a description of the specific
nature of such breach shall have been given by Purchaser to Seller prior to the expiration of said
one (1) year period and an action shall have been commenced by Purchaser against Seller within
ninety (90) days after the termination of such one (1) year survival period. As used herein, the
term “Cap” shall mean the total aggregate amount of Seven Hundred Fifty Thousand and Zero/100
Dollars ($750,000.00). In no event shall Seller’s aggregate liability to Purchaser under this
Agreement and the Related Contracts (hereinafter defined), for breach of any representation or
warranty of Seller under Article 3 of this Agreement or Article 3 of the Related Contracts, exceed
the amount of the Cap (it being understood, however, that the Cap shall not apply to any liability
that Seller may have to Purchaser, whether for breach of a representation or warranty or otherwise,
as a result of Seller’s fraud). Net proceeds from the Closing in a minimum amount equal to the Cap
shall be placed into escrow with Escrow Agent or, at Seller’s option, with Walker Title Company
(“Walker Title”) pursuant to the terms of an escrow agreement in substantially the form attached
hereto as Exhibit H until the later of the expiration of the one (1) year survival period
or the final resolution of any bona fide claim for which notice is given by Purchaser during such
survival period (the “Reps and Warranties Escrow”). In the event that Seller selects Walker Title
to act as the escrow agent for the Reps and Warranties Escrow, Seller shall pay any escrow or other
fee charged by Walker Title.

4. Inspection; Condition of Property and Title.

4.1 Right of Inspection. Purchaser shall have the right, at its own risk, cost and
expense, at any time prior to Closing during normal business hours (i.e., Monday through Friday
from 9:00 a.m. to 5:00 p.m. — federal holidays excepted) upon not less than twenty-four (24) hours
prior notice to Seller to enter, or cause its agents or representatives to enter, upon the Property
for the purpose of making surveys, tests, test borings, inspections, investigations and
architectural, structural, economic, environmental and other studies of the Property as Purchaser
may deem desirable. Purchaser agrees that it shall obtain Seller’s consent prior to contacting any
Tenant or entering or seeking to enter any Tenant’s premises at the Property, such consent not to
be unreasonably withheld, conditioned or delayed (but may be conditioned on allowing Seller to
monitor any communication and/or accompany Purchaser on any entry into a Tenant’s premises).
Seller agrees that it shall reasonably cooperate with Purchaser in connection with any other
information regarding the Property reasonably requested by Purchaser and will provide or make
available such information during the Inspection Period and at all periods thereafter through the
Closing to the extent either in Seller’s possession or control. Purchaser shall, at Purchaser’s
sole cost and expense, promptly and fully restore any damage or destruction to the Property
occurring as a result of any act or omission of Purchaser by reason of such tests, studies or
investigations. Purchaser shall indemnify, defend and hold Seller harmless from and against all
loss, cost, damage or claim (including attorneys’ fees reasonably incurred, court costs and costs
of investigation) arising out of or resulting from Purchaser’s exercise of the right and privilege
granted to Purchaser contained in this Article 4, and the undertakings contained in this Article 4
shall survive closing or prior termination of this Agreement. The obligations of Purchaser under
the immediately preceding sentence shall expressly survive any termination of this Agreement. The
parties acknowledge that Purchaser may be required to perform a historical audit of the Property in
order to comply with Item 3-14 of Regulation S-X promulgated under the Securities Act of 1933 and
the Securities Exchange Act of 1934. Seller shall, effective as of the Closing Date, make
commercially reasonable efforts to permit Purchaser’s auditors access at that location where Seller
customarily maintains its records, upon reasonable advance notice and during normal business hours,
to all of the Property’s books and records and the operating statements (certified by an officer of
the manager of Seller) and property management balance sheets for the Property for one (1) calendar
year prior to the Closing Date and for the period from the end of the prior fiscal year through the
Closing Date. To the extent that the originals or copies of same are not otherwise provided by
Seller to Purchaser at the Closing, and to the extent that the same are ordinarily maintained by
Seller in its normal course of business, such books and records shall include the detail general
ledger of profits and loss, accounts receivable records, rent rolls, billing records, accounts
payable records, and contracts. Purchaser’s access rights shall commence on the Closing Date and
shall continue until the successful completion of the audit and the filing of the 3-14 report with
the SEC (hereinafter defined), written notice of which shall be delivered promptly by Purchaser to
Seller; provided, however, that Seller’s obligation to provide access to Purchaser as described
above shall terminate on the first anniversary of the Closing Date. Notwithstanding anything to
the contrary in the foregoing, other than providing the access to Purchaser specified herein,
Seller shall not have any liability or responsibility in connection with or in any manner related
to, directly or indirectly, any audit required to be made by Purchaser or any compliance required
of Purchaser with any Regulation under the Securities Act of 1933 or the Securities Act of 1934.

4.2 Inspection Period. Purchaser’s obligations under this Agreement are subject to
Purchaser’s approval of the Property for Purchaser’s intended use and to satisfaction of certain
other contingencies more fully described in Article 5 below. Purchaser shall have the period
commencing on the date hereof and ending at 5:00 p.m. on August 8, 2006 (the “Inspection Period”)
to inspect the Property and to conduct such tests and investigations as it deems advisable in order
to determine that the Property can be used for Purchaser’s intended use. If, during the Inspection
Period, Purchaser in its sole discretion is not satisfied with the Property for any or no reason
whatsoever, Purchaser shall notify Seller in writing (prior to the expiration of the Inspection
Period) in which event:

	 	(i)	 	the Deposit shall be returned to Purchaser;

	 	(ii)	 	this Agreement shall be automatically terminated; and

	 	(iii)	 	the parties shall be relieved of any further obligation and responsibility
under this Agreement, subject only to the Purchaser’s obligations under Section 4.1
above.

It is expressly recognized and agreed by the parties that if Purchaser fails to notify Seller
in writing prior to the end of the Inspection Period that Purchaser elects to terminate this
Agreement pursuant to this Section 4.2, then Purchaser shall be deemed to have waived its
termination right under this Section 4.2, and, subject to the additional termination right set
forth in Section 4.3 below, the satisfaction of certain other contingencies more fully described in
Article 5 below and the terms of Article 10 and Section 11.2 below, the entire Deposit shall
thereupon be deemed at risk and non-refundable to Purchaser.

4.3 Additional Inspection for Title, Zoning and Survey Only. Purchaser will have the
additional right to terminate this Agreement at any time after the last day of the Inspection
Period and prior to 5:00 p.m. on August 15, 2006 (the “Extended Review Period”) should Purchaser be
dissatisfied with the status of the Property’s zoning compliance, the title commitment and/or the
ALTA survey obtained by Purchaser for the Property. If, during the Extended Review Period,
Purchaser determines in good faith that a zoning, title and/or survey problem or issue exists
which, in Purchaser’s reasonable opinion, materially affects the Property, then Purchaser may
notify Seller in writing prior to the expiration of the Extended Review Period that it wishes to
terminate this Agreement pursuant to this Section 4.3 (which notice will specify the particular
title, zoning and/or survey problem or issue identified by Purchaser), in which event:

	 	(i)	 	the Deposit shall be returned to Purchaser;

	 	(ii)	 	this Agreement shall be automatically terminated; and

	 	(iii)	 	the parties shall be relieved of any further obligation and responsibility
under this Agreement, subject only to the Purchaser’s obligations under Section 4.1
above.

It is expressly recognized and agreed by the parties that if Purchaser fails to notify Seller
in writing prior to the end of the Extended Review Period that Purchaser elects to terminate this
Agreement pursuant to this Section 4.3, then Purchaser shall be deemed to have waived its
additional termination right under this Section 4.3, and, subject to the satisfaction of certain
other contingencies more fully described in Article 5 below and the terms of Article 10 and Section
11.2 below, the entire Deposit shall thereupon be deemed at risk and non-refundable to Purchaser.

4.4 Title Commitment. Purchaser shall be responsible for obtaining a preliminary
title report for the Property after the Effective Date, and shall notify Seller in writing after
Purchaser’s receipt thereof whether any items shown on such title report are unacceptable to
Purchaser. Seller may, at its sole option, seek to cure any such title defects of which it is
notified on or before the expiration of the Extended Review Period. However, any title defects or
exceptions shown on Purchaser’s title report which Purchaser does not object to in writing prior to
the expiration of the Extended Review Period, or which remain uncured for any reason at the
expiration of Extended Review Period (regardless of whether or not Purchaser has objected thereto),
shall be deemed waived by Purchaser after the expiration of the Extended Review Period, all such
defects or exceptions shall thereafter constitute “Permitted Exceptions” for all purposes of this
Agreement. Notwithstanding the foregoing, Seller shall be obligated to remove by Closing, at
Seller’s sole cost, any and all monetary liens on or encumbrances to the Property arising from any
financing transaction, including without limitation, any mortgages, deeds of trust and financing
statements, with the exception of the Existing Indebtedness, without the necessity of Purchaser
providing any objection notice.

4.5 Assumption or Repayment of Existing Indebtedness. Purchaser shall provide Seller
with written notice prior to the expiration of the Inspection Period of Purchaser’s determination
to assume or pay off the Existing Indebtedness. In the event that Purchaser fails to timely
provide such written notice to Seller, Purchaser shall be deemed to have elected to assume the
Existing Indebtedness. In the event Purchaser elects to assume the Existing Indebtedness, then,
Purchaser and Seller shall work actively and in good faith with the Lender to ensure that the
Purchaser will be able to timely and satisfactorily assume the Existing Indebtedness at Closing.
In such event, Purchaser shall be responsible for the payment of Lender’s one percent (1%) loan
assumption fee, the attorney’s fees of Lender’s counsel, and all other reasonable costs and
expenses which may be charged by the Lender as a condition of approving the assumption thereof. In
the event that Purchaser elects to pay off the Existing Indebtedness, then: (i) the outstanding
principal balance of the Existing Indebtedness and any accrued and unpaid interest thereon owed as
of the Closing Date shall be paid by Purchaser and credited against the Purchase Price pursuant to
Section 2.2 above, but any cost of such repayment (e.g., costs of defeasance, yield maintenance
premiums, Lender’s fees and charges, etc.) charged by Lender or incurred by Purchaser in connection
with such repayment shall be bourn by Purchaser and not applied against the Purchase Price at
Closing, and (ii) if there is a credit on the loan payoff statement for reserves or escrows held by
Lender for the use or benefit of Seller which reduces the amount required to be paid by Purchaser
to repay the Existing Indebtedness, then such reduction amount shall be credited to Seller at
Closing.

Notwithstanding anything in this Agreement to the contrary, if Purchaser has elected to assume
the Existing Indebtedness, either party may terminate this Agreement by written notice to the other
at any time prior to the Closing Deadline (in which event the Deposit shall be returned to
Purchaser and neither party shall have any further obligations or liabilities to the other, subject
only to the obligations of the Purchaser under Section 4.1 above), and such termination shall not
be a default of the terminating party nor a willful failure by the terminating party to settle
hereunder, in the event that: (i) the Lender refuses to permit the assumption of the Loan by the
Purchaser, or is not ready to close on the assumption of the Loan by the Closing Deadline, for
reasons unrelated to the terminating party’s failure to cooperate actively and in good faith with
the Lender or to comply with any commercially reasonable requirements of the Lender not
inconsistent with this Agreement in connection with the Loan assumption, or (ii) the Lender imposes
commercially unreasonable requirements on the terminating party as a condition to permitting the
assumption of the Loan.

5. Conditions Precedent to Closing

5.1 Purchaser’s Conditions Precedent to Closing. It shall be a condition precedent to
Purchaser’s obligation to make a full settlement hereunder that each and every one of the following
conditions shall exist on the Closing Date:

	 	(i)	 	Representations and Warranties. Each of Seller’s representations and
warranties contained herein shall be true and correct in all material respects in the
same manner and with the same effect as though such representations and warranties had
been made on and as of the Closing Date. In addition, Seller shall have complied with
its obligations under Article 12 below as of the Closing Date;

	 	(ii)	 	Title Insurance. Purchaser shall have been able to secure a
commitment, naming Purchaser as the proposed insured, for an owner’s policy of title
insurance (“Title Policy”) for the Property. Upon Purchaser’s payment to the title
company of the stipulated title insurance premium, the Title Policy shall insure
Purchaser that, upon consummation of the purchase and sale herein contemplated at the
Closing, Purchaser will be vested with good, fee simple, marketable title to the
Property (having a legal description consistent with that set forth on the annexed
Exhibit A), free and clear of all encumbrances other than the Permitted
Exceptions and if Purchaser has elected to assume the Existing Indebtedness, liens
securing the Existing Indebtedness;

	 	(iii)	 	Condition of Property. Seller shall not have committed waste or
nuisance upon the Property and shall have maintained and kept the Property (including
the grounds thereof) in substantially the same order and condition as exists as of the
date hereof, normal wear, tear and obsolescence excepted. Seller shall not cause any
renovations, alterations or significant cosmetic changes to be made at or to the
Property prior to Closing except required repairs and any alterations or changes made
with Purchaser’s written consent (which consent shall not be unreasonably delayed,
withheld or conditioned). Seller shall not have undertaken or permitted any action
within Seller’s control, without the consent of Purchaser, which would impair or
otherwise affect the use, ownership, acquisition or development of the Property on or
after Closing in any material, adverse respect or which would cause any of the
representations or warranties set forth herein to be untrue in any material respect;

	 	(iv)	 	Estoppel Certificates. No later than five (5) days before the Closing
Date, Seller shall have obtained and delivered to Purchaser the original executed (a)
tenant estoppel certificates, dated no more than twenty-five (25) days prior to the
Closing Date, from Tenants occupying, in the aggregate, at least eighty (80%) of the
rentable square footage of the Building, in substantially the form set forth in
Exhibit E, or with such changes thereon as may be requested by any such Tenants
and approved by Purchaser and Seller (such approval not to be unreasonably withheld),
free from material adverse disclosures not previously disclosed to Purchaser in
writing, and (b) the CC&R estoppel certificate, dated no more than twenty-five (25)
days prior to the Closing Date, from Stafford Commerce Center Owners Association in
substantially the form set forth in Exhibit I attached hereto;

	 	(v)	 	Covenants of Seller. Seller shall have delivered those documents
required of Seller at Closing under Article 7 herein; and

	 	(vi)	 	Lender Approval. If Purchaser has elected to assume the Existing
Indebtedness, the Lender has approved such assumption of the Existing Indebtedness by
the Purchaser and, with respect to Stafford Commerce Center III and Stafford Commerce
Center IV (as defined in Section 6 below), the lender secured by such properties has
agreed to release the property known as Stafford Station from the cross-default and
cross-collateralization of the loan documents evidencing and/or securing such
indebtedness without any expense to or consideration from Purchaser (the “Stafford
Station Release”). In the event the owners of Stafford Commerce Center III and
Stafford Commerce Center IV are unable to obtain the Stafford Station Release by
Closing and this Agreement is terminated as a result of the failure to satisfy such
condition precedent to Purchaser’s obligation to close hereunder, Seller shall
reimburse Purchaser for its Pursuit Costs (as such term is hereinafter defined);
provided, however, that the Pursuit Costs required to be paid by Seller under this
Section 5.1 (vi) and under Section 5.1(vi) of the Related Contracts shall not exceed
$50,000 in the aggregate. This provision shall fully survive the expiration or earlier
termination of this Agreement.

5.2 Concurrent Closings. Concurrent with execution of this Agreement, Stafford
Commerce Center II, L.L.C., Stafford Commerce Center III, L.L.C., and Stafford Commerce Center IV,
L.L.C., each Virginia limited liability companies (the “Related Sellers”) controlled by the same
individuals as Seller, and Purchaser have entered into those certain other Agreements of Sale and
Purchase (the “Related Contracts”) for the properties known as Stafford Commerce Center Building
II, with a street address of 24 Center Street, Stafford, Virginia (“Stafford Commerce Center II”),
Stafford Commerce Center Building III, with a street address of 16 Center Street, Stafford,
Virginia (“Stafford Commerce Center III”) and Stafford Commerce Center Building IV, with a street
address of 10 Center Street, Stafford, Virginia (“Stafford Commerce Center IV”, and collectively
with Stafford Commerce Center II and Stafford Commerce Center III, the “Related Properties”).
Purchaser and Seller recognize and agree that the sale of the Property and Closing hereunder are
expressly conditioned upon the concurrent closings on the Related Properties by the applicable
Related Sellers and Purchaser or an entity or entities to be designated by Purchaser for the
purpose of acquiring the Related Properties (each, a “Related Purchaser”). If due to the default
of the Purchaser or any Related Purchaser, any of the Related Contracts terminates or the closing
on any of the Related Contracts shall not occur by the deadline for closing thereunder, such
default shall constitute a default under this Agreement and the provisions of Section 11.1 below
shall apply. If due to the default of the Seller or any Related Seller, any of the Related
Contracts terminates or the closing on any of the Related Contracts shall not occur by the deadline
for closing thereunder, any such default shall constitute a default under this Agreement. In such
event, Purchaser shall be entitled to elect its remedy under Section 11.2 herein, but Purchaser
agrees that it shall not be entitled to (i) waive the default hereunder and proceed to Closing on
this Agreement without closing on all of the Related Contracts, or (ii) pursue a suit for specific
performance hereunder unless Purchaser has elected to pursue specific performance on all of the
Related Contracts. If for any reason other than a Purchaser or Seller default, any of the Related
Contracts shall terminate in accordance with its terms or the closing on any of the Related
Contracts shall not occur by the deadline for closing thereunder, then this Agreement shall
automatically terminate, the Deposit shall be refunded to Purchaser and the parties shall be
released of all obligations hereunder other than the obligations of Purchaser under Section 4.1
above.

5.3 Failure of Condition to Purchaser’s Obligations. In the event of the failure of
any condition precedent set forth in Section 5.1 above as of the Closing Date, Seller shall have
the right to extend the Closing Date by written notice to the Purchaser on or prior to the Closing
Date for up to thirty (30) days in order to attempt to satisfy such condition. In the event of the
failure as of the Closing Date (as the same may have been extended) of any condition precedent set
forth above, Purchaser, at its sole election, may, at its option, either:

	 	(i)	 	terminate this Agreement, in which event the Deposit shall be returned to
Purchaser, whereupon neither party shall have any further obligations or liabilities to
the other, subject only to the obligations of the Purchaser under Section 4.1 above, or

	 	(ii)	 	waive the condition and proceed to Closing.

However, nothing contained herein shall be deemed to affect the rights of Purchaser under
Section 11.2 below in the event Seller has breached a representation or warranty made by Seller
under this Agreement or Seller shall willfully default on its obligations to settle on the
Property.

6. Closing. The purchase and sale contemplated herein shall be consummated at a settlement
(“Closing”) which shall take place on the date (the “Closing Date”) which is fifteen (15) days
after the date upon which Seller has received: (i) if Purchaser has elected to assume the Existing
Indebtedness, notice from Lender hereunder, which is also the mortgage lender for Stafford Commerce
Center II, that Lender has approved, and is ready to close on, the assumption by Purchaser and/or
Related Purchasers of both the Existing Indebtedness and the indebtedness to Lender secured by
Stafford Commerce Center II, and (ii) notice from the LaSalle Bank National Association, a national
banking association, or assigns, mortgage lender for Stafford Commerce Center III and Stafford
Commerce Center IV, that such lender has approved, and is ready to close on, the assumption by
Purchaser and/or Related Purchasers of the indebtedness secured by Stafford Commerce Center III and
Stafford Commerce Center IV (and such lender having agreed to release the property known as
Stafford Station from the cross-default and cross-collateralization provisions of the loan
documentation evidencing and/or securing such indebtedness without any expense to or consideration
from Purchaser). In no event, however, shall the Closing occur later than November 30, 2006 (the
“Closing Deadline”). If the Closing Date is not a Business Day, the Closing shall occur on the next
day which is a Business Day thereafter. The Closing shall be performed in escrow through the Escrow
Agent. The Closing shall take place during normal business hours on the Closing Date at the
offices of the Escrow Agent or at such other location as the parties may mutually agree.

7. Seller’s Deliveries. Seller shall execute, as appropriate, or cause to be executed, and
deliver to the Escrow Agent at Closing:

7.1 Deed. A special warranty deed (“Deed”) in such form as shall be reasonably
acceptable to the Escrow Agent and Purchaser’s counsel whereunder Seller grants and conveys fee
simple title to the Property;

7.2 Assignment of Leases. An agreement (the “Lease Assignment and Assumption
Agreement”) evidencing the Seller’s assignment and the Purchaser’s assumption of the Leases as of
the Closing Date in form and content reasonably acceptable to counsel for Purchaser and Seller;

7.3 Loan Assumption Documents. If Purchaser has elected to assume the Existing
Indebtedness, such commercially reasonable documents or instruments as the Lender may require to
effectuate the assignment by Seller and assumption by Purchaser of the Existing Indebtedness in
accordance with the Existing Loan Documents (the “Loan Assumption Documents”);

7.4 Option to Acquire Stafford Commerce Park Properties. An Option Agreement, in
substantially the form attached as Exhibit F hereto, from Stafford Commerce Park, LLC
granting to Purchaser (or to a direct or indirect subsidiary of Purchaser) the option, commencing
on the Closing Date and continuing until the third (3rd) anniversary of the Closing
Date, to acquire the properties known as Stafford Commerce Park I, Stafford Commerce Park II and
Stafford Commerce Park III on the terms described in Exhibit F;

7.5 Seller’s Affidavit. Such certificates, affidavits and other evidence signed and
delivered by Seller, as may reasonably be required to induce the title company to issue the Title
Policy, without exception except for the Permitted Exceptions and, if Purchaser has elected to
assume the Existing Indebtedness, the liens securing the Existing Indebtedness;

7.6 FIRPTA Affidavit. An affidavit certifying that Seller is not a “foreign person”
as that term is defined by Section 1445 of the Internal Revenue Code of 1986, as amended;

7.7 Resolutions. A certified true copy of Seller’s resolutions authorizing the sale
contemplated herein and the execution of this Agreement and all other documents delivered by Seller
at Closing and such other certificates, documents and instruments as may reasonably be required by
the title company to issue the Title Policy;

7.8 Bill of Sale and Assignment of Contracts. A bill of sale and an assignment of
contracts, each in form reasonably acceptable to Purchaser’s counsel, conveying to Purchaser all
Personalty and the Intangibles, and all of Seller’s right, title and interest, to the extent
assignable, in and to any (i) unexpired warranties and guarantees now in effect with respect to any
part of the Property and/or mechanical equipment and appliances at the Property, (ii) all
architectural, engineering, rezoning and subdivision plans (if any), specifications, drawings, and
reports, and (iii) all licenses and permits relating to the Property to the extent the same exist
and are assignable;

7.9 Possession; Keys. Possession of the Property and keys for the Improvements in the
possession or control of Seller or its agents;

7.10 Original Documents. The originals (or copies if originals are not available) of
all the Building Documents, including without limitation, the Leases;

7.11 Files. To the extent available, originals (or copies, if originals are not
available) of all documents and books and records necessary for the continued operation of the
Property, other than proprietary information, including without limitation, Lease files, rent
records, escalation records and statements and maintenance records;

7.12 Notice Letter to Tenants. Letters, in form acceptable to Purchaser’s counsel,
addressed to each of the Tenants, notifying the Tenants of the sale of the Property to Purchaser or
Related Purchaser, as applicable; and

7.13 Reps and Warranties Escrow. The Reps and Warranties Escrow agreement in
substantially the form attached hereto as Exhibit H as executed by Seller and Walker Title.

8. Purchaser’s Closing Obligations. Purchaser shall assume or pay off the Existing
Indebtedness, at its option as provided herein, and pay the remaining Purchase Price (as described
in Article 2 above), together with all other funds required hereunder to be paid by the Purchaser
in connection with the Closing, by federal wire transfer to the Escrow Agent on the Closing Date.
Purchaser shall also execute the Assignment and Assumption Agreement, the Loan Assumption
Documents, if applicable, and such other documents or instruments as the Escrow Agent or title
company may reasonably require in connection with the Closing. Additionally, Purchaser agrees to
take, at Seller’s sole cost and expense, any steps prior to or at Closing reasonably requested by
Seller in a written notice to Purchaser provided at least fifteen (15) days prior to Closing
(including, without limitation, the execution of reasonable documents) to further evidence or
perfect the cross-easements for parking set forth in Section 3.8 of the Declaration for Stafford
Commerce Center dated November 7, 2001 and recorded among the land records of Stafford County,
Virginia as Instrument 1 LR 010026943 (the “Declaration”). Seller shall be solely responsible for
any recording or other costs associated with any such documents. Additionally, for a period of one
(1) year after Closing hereunder, Purchaser will consider in good faith, but shall have no legal
obligation whatsoever to agree to or negotiate with regard to, any Seller request related to issues
regarding the physical or legal connections of the Property with the property known as Stafford
Station.

9. Settlement Charges; Prorations and Adjustments.

9.1 Allocation of Settlement Charges. Seller shall pay the cost of preparation and
recordation of the Deed. Purchaser shall pay the title examination fees and the title insurance
premium. Seller and Purchaser shall each pay half (1/2) of the Grantor’s Tax and Deed Recordation
Taxes and half (1/2) of the costs incurred by Purchaser to obtain an ALTA survey for the Property.
Other settlement expenses (except as otherwise expressly set forth in this Section 9.1) shall be
paid in accordance with the customs of real estate transactions in Stafford County, Virginia.
Seller shall be responsible at its sole cost and expense for the cost to release any existing liens
on the Property other than the Permitted Exceptions and other than the liens securing the Existing
Indebtedness (such Existing Indebtedness to be either assumed or prepaid by Purchaser in accordance
with this Agreement). Purchaser will pay one-half of the escrow fees of the Escrow Agent and
Seller shall be responsible for the balance of the escrow fees. Purchaser shall be solely
responsible for the costs incurred in connection with obtaining, executing, recording and insuring
any financing obtained by Purchaser. Purchaser and Seller each shall pay its own legal fees related
to the preparation of this Agreement and all documents required to settle the transaction
contemplated hereby.

9.2 Prorations and Adjustments. At Closing, interest on the Existing Indebtedness (if
being assumed by Purchaser), rents, all real property taxes, water rents, sewer charges, electric
and other utility charges, fuel if any, operating expenses, special assessments, if any, and other
similar charges affecting the Property shall be adjusted and prorated as of midnight of the day
prior to the Closing Date, the day of Closing being a day of income and expense for the Purchaser.
If Purchaser elects to assume the Existing Indebtedness, Seller shall assign to Purchaser at
Closing all of Seller’s right, title and interest in and to the reserves held by the Lender as of
the Closing Date, as described on Exhibit D hereto. The amount of reserves so assigned
will be credited to Seller and paid by Purchaser on the Closing Date. To the extent practicable,
Seller shall attempt to have utility providers read the meters for the Property on the day prior to
Closing for purposes of making such prorations and adjustments. All other charges or fees
customarily prorated and adjusted in similar transactions shall be adjusted at Closing. All
security deposits under the Leases (together with any accrued interest thereon as may be required
by law or contract) shall be paid or credited to Purchaser as of the date of Closing, and to the
extent Seller has any security deposits held in the form of a letter of credit, such letters of
credit shall be assigned to Purchaser as of the Closing Date, with any costs associated with
assigning the letters of credit to the Purchaser to be borne by the Seller. All rent (other
than prepaid rent) payable by the Tenants of the Property shall be adjusted (prorated) as of the
Closing Date and paid in accordance with the following provisions:

	 	(i)	 	Any Basic Rent and any monthly estimated common area maintenance (“CAM”) and
real estate tax payments, and any other monthly charges under any of the Leases which
are attributable to the month in which the Closing occurs, shall be adjusted as of the
Closing, with Seller being entitled to the portion thereof attributable to the period
of the month immediately preceding the Closing Date and Purchaser entitled to the
balance of such monthly installment. The party receiving such payment after Closing
shall pay over to the other party within five (5) Business Days following receipt, the
portion of the installment to which the other party is entitled.

	 	(ii)	 	Purchaser shall be entitled to all Basic Rent and other sums due under the
Leases to the extent collected on any date after the Closing, with the exception of (a)
any common area maintenance (CAM), tax and insurance adjustment payments by Tenants
attributable to periods prior to the Closing, as described in this Subsection (ii)
below; (b) the Basic Rent, estimated CAM charge payments and other monthly charges for
the Closing month to which Seller is entitled under (i) above, and (c) to the extent
specified in Subsection (iii) below, rentals paid by the Tenants on account of rental
arrearages for periods preceding the Closing. Any CAM, tax or insurance adjustment
payments by Tenants which are payable on an annual basis after the conclusion of each
calendar year will be adjusted as of Closing, with Seller being entitled to the portion
thereof attributable to the period of the year immediately preceding the Closing Date
and Purchaser being entitled to the balance of such payment.  Purchaser shall pay over
to Seller within five (5) Business Days following receipt the portion of the
installment to which the Seller is entitled (which such payment shall be accompanied by
a statement showing Purchaser’s calculation of Seller’s pro rata portion). Purchaser
agrees that adjustment billings to Tenants for CAM, taxes or insurance premiums for the
accounting year in which the Closing occurs shall be billed by Purchaser to Tenants on
a timely basis in accordance with the respective Leases (and Seller hereby agrees to
cooperate with Purchaser in determining the amount of such adjustment billings).
Additionally, any post-Closing tenant payments of amounts for special services provided
by Seller prior to the Closing Date which were specifically billed by Seller prior to
the Closing Date shall be remitted by Purchaser to Seller within five (5) Business Days
following Purchaser’s receipt thereof.

	 	(iii)	 	Rent which is due, but uncollected, as of the Closing shall not be adjusted,
but Purchaser shall cause the rent for the period prior to Closing to be remitted to
Seller if, as and when collected, less any reasonable, out-of-pocket expenses incurred
by Purchaser for such collection; provided, that, except with respect to Basic Rental
for the Closing month, which shall be treated as specified in (i) above, all rents
collected subsequent to Closing by Purchaser shall first be applied to current rentals
then due which have accrued subsequent to Closing and any remaining amounts shall be
applied to rental arrearages as of Closing. Similarly, if Seller receives any Basic
Rent or other sums under the Leases which are payable to Purchaser under this Section
9.2, then Seller shall promptly deliver such sums to Purchaser. Purchaser, at Seller’s
request, will use reasonable efforts for a period of ninety (90) days after the Closing
Date to collect past due rental amounts or other payments owed to Seller in accordance
with this Section 9.2. Seller shall have no right to take any collection actions
against Tenants.

All adjustment items to the extent they cannot be precisely determined at Closing (or to the extent
found to be erroneous after the Closing), shall be estimated at Closing and shall be resolved by
the parties in good faith no later than sixty (60) days after the Closing.

9.3 Release of Closing Escrow. Upon receipt of Purchaser’s deliveries required under
Article 8 above, and subject to all of Seller’s deliveries having been received and such other
conditions to Purchaser’s performance as are contained in Section 5 hereof, Escrow Agent shall
record the Deed, disburse the settlement proceeds as indicated on the settlement sheets, and
distribute all Closing documents as directed by counsel for Purchaser and Seller.

10. Condemnation and Risk of Loss. The risk of condemnation of all or any portion of the
Property or loss or damage to the Property by fire or other casualty shall be borne by Seller until
recordation of the Deed. In the event of (i) the threatened or actual commencement of eminent
domain proceedings or actual condemnation or taking of all or any part of the Property, or (ii)
damage to the Property by fire or other casualty, act of God or any other event on or prior to the
Closing Date, which would cost in excess of One Hundred Fifty Thousand Dollars ($150,000) to
repair, Purchaser, at its sole option exercisable within thirty (30) days following receipt of
written notice of the event giving rise to the exercise of such option, shall have the right to
terminate this Agreement, in which event the Deposit shall be returned to Purchaser, and neither
party shall have any further obligations or liabilities to the other, subject to the obligations of
the Purchaser under Section 4.1 herein. Purchaser understands and agrees that if it does not
exercise its termination option in the event of condemnation or casualty as described above, the
terms and conditions of the documents governing the Existing Indebtedness will control the use of
any insurance proceeds and the settlement of any insurance claims related thereto, and that
Purchaser will have no rights with respect to such proceeds or claims. In the event of casualty,
the repair of which would cost less than One Hundred Fifty Thousand Dollars ($150,000), Seller
shall assign all insurance proceeds to Purchaser at Closing and Purchaser shall receive a credit at
Closing for the amount of any deductible under Seller’s insurance. The provisions of this
Article 10 shall expressly survive Closing and delivery of the Deed for the Property.

11. Default Provisions; Remedies.

11.1 Purchaser’s Default. If Purchaser fails to consummate the purchase and sale
contemplated herein after all conditions precedent to Purchaser’s obligation to consummate the
transactions herein contemplated have been satisfied or waived by Purchaser, or if, pursuant to
Section 5.2 above, any Related Purchaser has defaulted under any of the Related Contracts, and if
Seller or the applicable Related Seller has notified Purchaser or such Related Purchaser of such
default and Purchaser or such Related Purchaser has failed to cure such default within ten (10)
days after such notice, then Escrow Agent shall deliver to Seller the Deposit. In such event the
Deposit shall be deemed as full and complete liquidated damages and the sole and exclusive remedy
of Seller, the parties hereby agreeing that they have considered carefully the loss to Seller that
would be a consequence of such default and that the Deposit is a reasonable estimate of such loss.
Upon payment to Seller of the Deposit, this Agreement shall terminate, and neither party shall have
any further obligations or liabilities to any other party, other than any obligations or
liabilities which expressly survive any termination of this Agreement.

11.2 Seller’s Default. If Seller breaches any of its representations, warranties,
covenants and/or agreements hereunder or fails to consummate the purchase and sale contemplated
herein by the Closing Date, or if, pursuant to Section 5.2 above, any Related Seller has defaulted
under any of the Related Contracts, and if Purchaser or the applicable Related Purchaser has
notified Seller or such Related Seller of such default and Seller or such Related Seller has failed
to cure such default within ten (10) days of such notice, then Purchaser shall be entitled at its
option to notify Seller of the election by Purchaser to terminate this Agreement, whereupon Escrow
Agent shall return the Deposit to Purchaser and neither party will have any further obligation to
the other hereunder, other than the obligations of the Purchaser under Section 4.1 (provided
Purchaser may only elect to terminate this Agreement because of a default under a Related Contract
if the respective Related Purchasers have also terminated all the Related Contracts due to such
default). Alternatively, in the event Seller shall willfully fail to close as required hereunder,
Purchaser at its election shall be entitled to bring suit for specific performance, inasmuch as the
parties recognize and acknowledge that the Property is unique, and that there is no adequate remedy
at law to compensate fully Purchaser for a breach by Seller of Seller’s obligations to convey the
Property to Purchaser in accordance with the terms and conditions of this Agreement. In no event
shall Purchaser be entitled to monetary damages for a failure of Seller to close hereunder, with
the exception that in the case of a willful failure of Seller to close hereunder after the
foregoing ten (10) day notice and cure period, and provided that in the absence of such failure to
close Purchaser would have been ready, willing and able to close, Purchaser shall be entitled to
recover from Seller Purchaser’s reasonable, out-of-pocket due diligence costs and expenses incurred
in connection with this Agreement, including reasonable attorney’s fees (collectively, the “Pursuit
Costs”).

For purposes of this Agreement, a willful failure or default of Seller is a failure or default
which was within Seller’s knowledge and reasonable control to prevent. This Section 11.2 shall
fully survive the expiration or earlier termination of this Agreement.

12. Obligations of Seller Pending Closing. Between the date hereof and the Closing Date:

12.1 Occupancy at Closing. The parties understand that the Property will be delivered
subject only to the rights of the Tenants.

12.2 Leasing. Seller agrees that it will not enter into any new leases for premises
in the Property, extend or modify any of the existing Leases or enter into any other new agreements
affecting the Property without the Purchaser’s consent, which consent shall not be unreasonably
delayed, withheld or conditioned. Notwithstanding the foregoing, Seller may freely enter into any
ordinary and necessary service agreement affecting the Property without Purchaser’s consent if the
agreement shall by its terms terminate or be terminable at will by the Seller prior to Closing,
provided that Seller shall give written notice of any such agreement to the Purchaser promptly
after execution thereof.

12.3 Maintenance and Operation of Property. Seller shall continue to maintain the
Property consistent with its prior practices, in order that its present operating condition be
maintained in good and proper repair, order and condition, normal wear and tear excepted, and shall
cause the continuation of the normal operation thereof, including the purchase and replacement of
supplies and equipment. Seller shall not remove or permit to be removed from the Property any
Personalty, except as may be necessary for repairs or discarding worn out or useless items,
provided that discarded items shall be replaced with new items of substantially equal quality and
quantity and shall be free and clear of any lien or encumbrance.

12.4 No Action. Seller shall not knowingly take any action or direct, require or
advise any other person or entity to take any action that would invalidate, void or make untrue any
representation or warranty provided under this Agreement or otherwise breach this Agreement.

12.5 Additional Deliveries. Seller shall deliver to Purchaser promptly following its
receipt copies of any notices received by Seller or its management agent from the holder of any
liens existing against the Property or from any Tenants pertaining to the Property from and after
the date hereof through Closing.

12.6 Scheduled Payments of Existing Indebtedness. Seller will make the scheduled
monthly payments of principal and interest under the Existing Indebtedness until Closing.

13. Non-Compete; List of Other Properties. For a period commencing on the Closing Date and
ending on the third (3rd) anniversary of the Closing Date, neither Seller nor any Seller
affiliate (as defined below) will market to or enter into a lease with any then-existing Tenant of
the Property for any office space for lease at a competitive property owned by Seller or such
Seller affiliate within a three (3) mile radius of the Property, so long as there is enough
available space at the Property to accommodate such Tenant’s space needs. Provided for information
purposes only, attached as Exhibit G hereto is a list, current as of the Effective Date, of
all of the office developments owned or under active planning by Andrew S. Garrett or his
affiliates within ten (10) miles of the Property. For purposes of this Article 13, the term
“Seller affiliate” shall mean Stafford Commerce Park, LLC and any entity in which Andrew S. Garrett
holds, directly or indirectly, a controlling interest.

14. Miscellaneous Provisions.

14.1 Completeness and Modification. This Agreement constitutes the entire agreement
between the parties hereto with respect to the transactions contemplated herein, and it supersedes
all prior discussions, understandings or agreements between the parties. This Agreement shall not
be modified or amended except by an instrument or writing signed by and on behalf of the parties.

14.2 Additional Documents. Purchaser and Seller agree that they will, at any time
after the Closing, duly execute and deliver to each other any additional conveyances, assignments,
documents and instruments, and shall take or cause to be taken such further actions (including the
making of filings), which are necessary in connection with the consummation of the purchase and
sale contemplated herein.

14.3 Severability. If fulfillment of any provision of this Agreement, or performance
of any transaction related hereto, at the time such fulfillment or performance shall be due, shall
involve transcending the limit of validity prescribed by law, then the obligation to be fulfilled
or performed shall be reduced to the limit of such validity; and if any clause or provision
contained in this Agreement operates or would prospectively operate to invalidate this Agreement in
whole or in part, then such clause or provision only shall be held ineffective, as though not
herein contained, and the remainder of this Agreement shall remain operative and in full force and
effect.

14.4 Cumulative Remedies. Except as specifically provided in this Agreement, each and
every of the rights, benefits, and remedies provided to Purchaser or Seller by this Agreement, or
any instruments or documents executed pursuant to this Agreement, are cumulative and shall not be
exclusive of any other rights, remedies and benefits allowed to such party by this Agreement, at
law or in equity.

14.5 Construction. Each party hereto hereby acknowledges that all parties hereto
participated equally in the negotiation and drafting of this Agreement and that, accordingly, no
court construing this Agreement shall construe it more stringently against one party than against
the other.

14.6 Pronouns. All pronouns and any variations thereof shall be deemed to refer to
the masculine, feminine, neuter, singular or plural, as the identity of the person or entity may
require.

14.7 Binding Effect; Assignment. This Agreement shall be binding upon and inure to
the benefit of the parties hereto, and their respective successors and permitted assigns.
Purchaser may not assign this Agreement to any person or entity other than a direct or indirect
subsidiary of Purchaser without the prior written consent of Seller, which consent shall not be
unreasonably withheld, conditioned or delayed. In the event of an assignment by Purchaser to a
direct or indirect subsidiary of Purchaser, Purchaser shall remain liable for the performance of
the obligations of Purchaser hereunder, unless and until expressly released by Seller. Seller
shall not assign this Agreement.

14.8 Waiver; Modification. Failure by Purchaser or Seller to insist upon or enforce
any of its rights hereto shall not constitute a waiver thereof.

14.9 Governing Law. This Agreement shall be governed by and construed under the laws
of the state of Virginia.

14.10 Headings. The headings are used herein for convenience of reference only, and
shall not be deemed to vary the content of this Agreement.

14.11 Exhibits. All Exhibits attached hereto are incorporated herein and made a part
of this Agreement.

14.12 Counterparts. To facilitate execution, this Agreement may be executed in as
many counterparts as may be required; and it shall not be necessary that the signature of each
party, or that the signatures of all persons required to bind any party, appear on each
counterpart; but it shall be sufficient that the signature of each party or that the signatures of
the persons required to bind any party, appear on one or more such counterparts. All counterparts
shall collectively constitute a single agreement. This document and any amendment hereto may be
executed by facsimile and any such facsimile shall be deemed to constitute an original for all
purposes hereof.

14.13 Notices. All notices, requests, consents, and other communications hereunder
shall be in writing and shall be personally delivered, sent by facsimile transmission, sent by
Federal Express or other recognized overnight delivery service, prepaid by the party sending such
notice, to the addresses indicated below.

	 	 	 
	If intended for Seller to:

With a copy to:

If intended for Purchaser to:

With a copy to:

	 	Stafford Commerce Center, L.L.C.

c/o Garrett Development Corporation

25 Center Street, Suite 101

Stafford, Virginia 22556

Fax No. (540) 659-3449

Attention: Andrew S. Garrett

Foley Hoag LLP

1875 K Street, N.W., Suite 800

Washington, D.C. 20006

Fax No. (202) 467-9630

Attention: Stephanie Cutler, Esq.

Columbia Equity Trust, Inc.

1750 H Street, N.W., Suite 500

Washington, D.C.

Fax No. (202) 303-3088

Attention: Clinton D. Fisch

Watt Tieder Hoffar & Fitzgerald, L.L.P.

8405 Greensboro Drive, Suite 100

McLean, Virginia 22012

Fax No. (703) 749-0479

Attention: Colin J. Smith, Esq.

The addresses and parties set forth above may be changed from time to time by any party by
notice to the other. For purposes of this Agreement, notices shall be effective upon receipt or
refusal thereof.

14.14 Business Day. As used herein, the term “Business Day” shall mean any day other
than a Saturday or Sunday, or other day recognized as a holiday by the U.S. Government. All times
specified hereunder shall be deemed to be Eastern Standard/Daylight Times.

14.15 Survival. It is the express intention and agreement of the parties hereto that
the covenants, agreements, statements, representations and warranties made in this Agreement by
Seller and Purchaser shall survive the execution and delivery of this Agreement for one (1) year
following Closing (except for the three (3) year survival periods described in Section 7.4 and
Article 13 above).

14.16 Attorneys’ Fees. If Purchaser institutes any proceeding or action to obtain
specific performance by Seller of its closing obligations hereunder, or if either party institutes
any proceeding or action to obtain any other relief under this Agreement, the non-prevailing party
shall in such event reimburse the other party for reasonable, out-of-pocket costs and other
expenses, including reasonable attorneys’ fees, incurred in connection with such proceeding or
action.

14.17 Waiver of Jury. SELLER AND PURCHASER EACH HEREBY IRREVOCABLY WAIVES TRIAL BY
JURY IN ANY ACTION OR PROCEEDING BROUGHT BY OR AGAINST THE OTHER PARTY UNDER OR IN CONNECTION WITH
THIS AGREEMENT.

14.18 Brokerage Commission. Seller and Purchaser represent and warrant to each other
that they have dealt with no brokers or finders in connection with the sale of the Property other
than Grubb & Ellis (the “Broker”) and that no brokerage fee or real estate commission is or shall
be due or owing in connection with this transaction other than to the Broker, who shall be paid
solely by Seller from the proceeds at Closing in accordance with the terms of a separate written
agreement with Seller. Seller and Purchaser hereby indemnify and hold the other harmless from any
and all loss, costs or damage (including, without limitation, reasonable attorneys fees and
expenses) arising out of any claims of any broker or agent so claiming based on action or alleged
action of the indemnifying party recognizing the Seller alone shall bear the cost of the Broker as
aforesaid. This Section 14.18 shall survive Closing.

14.19 Exclusivity. Seller agrees that it will not (either directly or indirectly)
offer to sell, or solicit any offers to purchase or negotiate for the sale or disposal of the
Property with any other party other than the Purchaser and its affiliates prior to Closing or an
earlier default by the Purchaser hereunder (beyond any applicable notice and cure period) or
termination of this Agreement in accordance with its terms.

14.20 Confidentiality. Each party agrees that, except as otherwise set forth in this
Agreement or required by law or legal process, it shall: (i) keep the contents of this Agreement
and any information related to the transaction contemplated hereby confidential (except that
Purchaser and Seller may disclose such data and information to their respective employees, lenders,
consultants, accountants and attorneys, provided that such persons agree to treat such data and
information confidentially); and (ii) refrain from generating or participating in any publicity
statement, press release or other public notice regarding this transaction without the prior
written consent of the other party unless required under applicable law or by legal process;
provided, however, that Purchaser and Seller may at or following the Closing publicly announce the
sale of the Property and the identity of the new owner thereof. The provisions of this Section
14.20 shall survive the Closing. Seller acknowledges that Purchaser is a publicly traded real
estate investment trust. Notwithstanding the foregoing confidentiality provisions, Seller
acknowledges that the rules and regulations promulgated by the United States Securities and
Exchange Commission (the “SEC”) may require Purchaser to disclose certain basic information
concerning this Agreement and the transactions contemplated herein in documents to be filed with
the SEC. The parties agree that Purchaser shall be permitted to make such disclosures and that
such disclosures shall not constitute a breach or a violation of this Section 14.20 or any other
confidentiality or non-disclosure agreement executed by the parties prior to the Effective Date.
Such confidentiality or non-disclosure agreement, if any, shall be amended and modified to the
extent provided in this Section 14.20.

14.21 Tax Deferred Exchange. Purchaser and Seller agree that, at either Purchaser or
Seller’s sole election, this transaction shall be structured as an exchange of like-kind properties
under Section 1031 of the Internal Revenue Code of 1986, as amended (the “Code”), and the
regulations and proposed regulations thereunder. The parties agree that if either wishes to make
such election, it must do so prior to the Closing Date. If either so elects, the other shall
reasonably cooperate, provided any such exchange is consummated pursuant to an agreement that is
mutually acceptable to Purchaser and Seller and which shall be executed and delivered on or before
the Closing Date. The electing party shall in all events be responsible for all costs and expenses
related to the Section 1031 exchange and shall fully indemnify, defend and hold the other harmless
from and against any and all liability, claims, damages, expenses (including reasonable attorneys’
fees and reasonable attorneys’ fees on appeal), proceedings and causes of action of any kind or
nature whatsoever arising out of, connected with or in any manner related to such 1031 exchange
that would not have been incurred by the non-electing party if the transaction were a purchase for
cash. The provisions of the immediately preceding sentence shall survive closing and the transfer
of title to the Property to Purchaser. In no event will the Closing be delayed because of any
circumstances relating to the Section 1031 exchange. Notwithstanding anything to the contrary
contained in this paragraph, any such Section 1031 exchange shall be consummated through the use of
a facilitator or intermediary so that Purchaser shall in no event be requested or required to
acquire title to any property other than the Property.

[THE BALANCE OF THIS PAGE HAS BEEN LEFT BLANK INTENTIONALLY]

1

IN WITNESS WHEREOF, the parties hereto have executed this Agreement under seal as of the day
and year first above written.

	 	 	 	 	 	 	 	 	 	 	 
	
 
	 	 	 	PURCHASER:
	 	

	 	

	 	

	 
	 	 	 	 	 	 	 	 	 	 
	 	 	 	 	 
	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	ATTEST:	 	 	 	COLUMBIA EQUITY TRUST, INC., a Maryland corporation
	 	 	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	/s/Ed Schulze

	 	 	 	By:
	 	/s/Clinton D. Fisch
	 	

	 	

	 
	 	 	 	 	 	 	 	 	 	 
	 
	 	 	 	 
	 	 
	 
	 	 	 	 	 	 	 	 	 	 
	Name:

Title:

	 	Ed Schulze

Vice President
	 	 	 	Name:

Title:
	 	Clinton D. Fisch

Senior Vice President
	 	

	 	 	 	 	 	 	 	 	 	 	 
	(CORPORATE SEAL)
	 	 	SELLER:
	WITNESS: STAFFORD COMMERCE CENTER, LLC, a Virginia limited liability company
	By:Garrett Development Corporation, Its Manager
	/s/Sandy Winkler	 	By:/s/Andrew S. Garrett
	Name: Sandy Winkler Andrew S. Garrett, President
	Title: Comptroller
	(CORPORATE SEAL)By:Cutler Development Corporation, Its Manager
	/s/Paul Salditt	 	By:/s/Miriam J. Cutler
	Name: Paul Salditt Miriam J. Cutler, President
	Title:
	(CORPORATE SEAL)
	ACCEPTED AND AGREED BY ESCROW AGENT:
	COMMERCIAL TITLE GROUP, INC.
	By: /s/Douglas A. Nichols
	Name:	 	Douglas A. Nichols
	Title:	 	President

Andrew S. Garrett hereby executes this Agreement solely for the purpose of evidencing his
agreement, pursuant to Article 13 herein, not to take any action to cause or allow any of Seller’s
affiliates (as defined in Article 13 hereof) to violate the covenant not to compete set forth in
Article 13 hereof.

/s/Andrew S. Garrett

Andrew S. Garrett

2

	 	 	 
	LIST OF EXHIBITS	 	 
	EXHIBIT A

EXHIBIT B

EXHIBIT C

EXHIBIT D

EXHIBIT E

EXHIBIT F

EXHIBIT G

EXHIBIT H

EXHIBIT I

	 	Legal Description

Schedule of Leases

Schedule of Service Contracts

List of Loan Documents for Existing Indebtedness and Statement of Reserves

Form of Tenant Estoppel Certificate

Form of Option Agreement

List of Properties Within 10 Mile Radius

Reps and Warranties Escrow Agreement

Form of CC&R Estoppel Certificate

3

EXHIBIT A

Legal Description

All of the following parcels of real property situated in Stafford County, Virginia namely:

See attached descriptions contained on 1 page

4

EXHIBIT B

Schedule of Leases

5

EXHIBIT C

Schedule of Service Contracts

6

EXHIBIT D

List of Loan Documents for Existing Indebtedness and Statement of Reserves

A. LIST OF LOAN DOCUMENTS FOR EXISTING INDEBTEDNESS

1. Deed of Trust Note

2. Deed of Trust

3. UCC-1 Financing Statements

4. Assignment of Leases and Rents

5. Non-Recourse Carve-Outs Guaranty

6. Environmental and Hazardous Substance Indemnification Agreement

7. Affidavit of Title

8. Loans to One Borrower Certificate

9. Manager’s Consent and Subordination of Management Agreement

10. Certificate (Operating Statements)

11. Certificate (Rent Roll)

12. Certificate (Licenses, Permits, Consents and Approvals)

13. Copy of completed, dated Opinion of Borrower’s Counsel

14. Mortgagee Protective Agreement

B. STATEMENT OF RESERVES

	 	 	 	 	 
	Tax Reserve Balance
	 	$	9,871.28	 
	Insurance Reserve Balance
	 	$	9,247.28	 
	T.I. and Capital Improvement Reserve
	 	$	195,668.24	 
	Total Reserve Balance
	 	$	214,786.80	 

7

EXHIBIT E

Form of Tenant Estoppel Certificate

________, 2006

Columbia Equity Trust, Inc. (“Purchaser”)

1750 H Street, NW

Suite 500

Washington, D.C. 20006

	 	 	 	 	 
	Re:

	 	Building Address:
	 	25 Center Street

Stafford, Virginia (the “Property”)

Ladies and Gentlemen:

It is our understanding that Stafford Commerce Center, L.L.C., a Virginia limited liability
company (“Seller”) proposes to transfer the ownership of the Property to Purchaser. As a condition
precedent of Purchaser acquiring the Property, Seller and Purchaser have required this
certification of the undersigned.

The undersigned, as Tenant, under that certain Lease Agreement, dated      , 200     , as
amended by that certain      (the “Lease”), for rentable area on the      floor of the
Property (the “Leased Premises”), made with Seller, as Landlord, hereby ratifies the Lease and
certifies to Seller, Purchaser and Lender (as hereinafter defined) that:

	1.	 	The current annual Basic Rent payable pursuant to the terms of the Lease is $    per
annum; and further, additional rent pursuant to the Lease is payable as follows: Tenant pays
its pro-rata share (such pro-rata share being equal to      %) of Operating Expenses in excess
of the Operating Expense Base of $     ; and

	2.	 	The Lease is in full force and effect and has not been assigned, modified, supplemented or
amended in any way except as noted above; and

	3.	 	The Lease represents the entire agreement between Seller and Tenant as to the Leased
Premises. All capitalized terms used herein but not defined shall be given the meaning
assigned to them in the Lease; and

	4.	 	On this date there are no existing defenses or offsets, claims or counterclaims which the
undersigned has against the enforcement of the Lease by Seller; and

	5.	 	No rental has been paid in advance and no security has been deposited with Seller except for
a security deposit in the amount of $     ; and

	6.	 	The total rentable floor area of the Leased Premises is      rentable square feet; and

	7.	 	On the date of this certification there are no existing breaches or defaults by Seller or
Tenant under the Lease that are known to Tenant; and

	8.	 	The term of the Lease commenced on      , 200     . The Rent Commencement Date under the
Lease was      , 200     . The Lease will expire on      , 20     . The Tenant
has no option to purchase all or any part of the Property or any option to terminate or cancel
the Lease. The Lease provides for [no or      (     )      -year] extension options; and

	9.	 	Tenant has accepted possession of the Leased Premises and there are no outstanding Landlord
obligations to perform tenant improvements.

	10.	 	Tenant has not transferred, assigned, or sublet any portion of the Leased Premises nor
entered into any license or concession agreements with respect thereto except as follows (if
none, please state “none”):      

	11.	 	All monthly installments of Basic Rent and Operating Expense Increases have been paid when
due through      , 200     . The current monthly installment of Basic Rent is
$     and the current monthly installment of Operating Expense Increases is
$     .

	12.	 	Tenant’s current address for notices under the Lease is:

     

     

     

Attn:      

	13.	 	The Guaranty of Lease dated      , 200     from      , a
     , has been duly executed and delivered, is unamended and is in full force and
effect.

Tenant acknowledges that this certificate may be delivered to Purchaser and its mortgage
lender (“Lender”) and their respective successors and assigns, and acknowledges that such persons
will be relying upon the statements contained herein in acquiring the Property or disbursing loan
advances or making a new loan secured by the Property and that receipt of this certificate by
Lender and Purchaser is a condition of disbursing loan advances or making such loan or acquiring
the Property, respectively. Without limitation, any entity formed by Purchaser to purchase the
Property may rely upon this Certificate.

IN WITNESS WHEREOF, the undersigned has caused this certificate to be executed as of the      
day of      , 2006.

     , a      

By      

Its      

8

EXHIBIT F

Form of Option Agreement

OPTION AGREEMENT

THIS OPTION AGREEMENT, made this      day of      , 2006 (the “Effective Date”), by and
between STAFFORD COMMERCE PARK, L.L.C., a Virginia limited liability company (“Optionor”), and
COLUMBIA EQUITY TRUST, INC., a Maryland corporation or its permitted assigns (collectively,
“Optionee”).

WITNESSETH:

WHEREAS, the Optionor is the owner of certain property consisting of three (3) parcels of
land, with the buildings and improvements erected or to be erected thereon, located in Stafford
County, Virginia, and commonly known as (i) Stafford Commerce Park Building I, a completed office
building with a street address at 65 Barrett Heights Road, Stafford, Virginia (“SCP I”), Stafford
Commerce Park Building II, an office building for which construction has commenced and with a
street address of 75 Barrett Heights Road, Stafford, Virginia (“SCP II” and, together with SCP I,
the “Buildings”) and Stafford Commerce Park Building III, presently a pad site with no construction
commenced (“SCP III” and, collectively with the Buildings, the “Property”).

WHEREAS, the Optionee desires an option to purchase the Property and the Optionor is willing
to give said option; and

WHEREAS, Stafford Commerce Center, LLC, Stafford Commerce Center II, LLC, Stafford Commerce
Center III, LLC and Stafford Commerce Center IV, LLC (each an “SCC Owner” and collectively, the
“SCC Owners”), each being an entity owned under the same or a substantially similar ownership
structure as Optionor, have each entered into a Purchase and Sale Agreement dated as of July      ,
2006 (collectively, the “SCC Purchase Agreements”) for the purchase by the Optionee or permitted
assigns of certain real property owned by each such SSC Owner in the immediate vicinity of the
Property; and

WHEREAS, the SCC Purchase Agreements each entitle the Optionee to condition its closing
thereunder on the provision of an option for the purchase of the Property; and

WHEREAS, the parties desire to confirm in writing their understandings and agreements
pertaining to the foregoing.

NOW, THEREFORE, in consideration of the mutual covenants herein set forth and in consideration
of the sum of Ten Dollars ($10.00) by each in hand paid to the other, receipt of which is hereby
acknowledged, the Optionor and the Optionee hereby agree as follows:

1. Grant of Option. The Optionor does hereby grant to the Optionee the exclusive option
(the “Option”) to purchase the Property during the Option Term (defined in Section 3 below) and on
the other terms and conditions set forth in this Option Agreement. The Property is more
particularly defined on Exhibit A attached hereto and made a part hereof. The Property may
be purchased in a single transaction involving the contemporaneous acquisition of the entire
Property, or, at Optionee’s option, the Option may be exercised just with respect to the two (2)
Buildings together (separate from SCP III, but not separate from each other) and/or just with
respect to SCP III (separate from the Buildings) in either case, on terms set forth below. In the
event that Optionee exercises its Option just with respect to the Buildings or just with respect to
SCP III, as applicable, its Option shall remain in effect with respect to the remaining portion of
the Property for the remainder of the Option Term. Optionor shall not have the right to sell,
transfer or convey any ownership interest in or to any portion of the Property during the Option
Term except (a) in connection with a separation of SPC III and the two Buildings into two or three
separate ownership entities, as may be beneficial for financing or other bona fide business
purposes, as long as each of such ownership entities has the same ownership structure as the
ownership structure of the Optionor, and provided that in the case of such a separation of
ownership, the Optionor and such separate ownership entities will enter into such amendment(s) to
this Option Agreement and/or other documents as the Optionee may reasonably request to ensure that
all of the terms of this Option Agreement remain in full force and effect and binding against all
parts of the Property and the ownership entities of the Property in the same manner as provided
herein, and (b) otherwise as pursuant to the terms of this Option Agreement.

2. Option Consideration. The consideration for the Option is the mutual promises and
agreements set forth in the Purchase Agreements and herein.

3. Term of Option. The term of the Option (the “Option Term”) shall commence as of the
Effective Date hereof and, unless earlier voided in accordance with the terms hereof, shall
continue until the third (3rd) anniversary of the Effective Date (the “Option
Termination Date”).

4. Inspection Period and Option Exercise.

(a) If the Optionee determines that it may wish to exercise the Option as to the Buildings, as
to SCP III or as to the entire Property, as applicable (the “Option Property”), it shall first
deliver a notice of interest to the Optionor pursuant to Section 7 below (the “Notice of
Interest”). Such Notice of Interest shall be delivered no later than ninety (90) days prior to the
Option Termination Date (the “Option Notice Deadline”). If such Notice of Interest is not received
by the Option Notice Deadline, this Option Agreement will be null and void and neither party will
have any further obligation to the other hereunder. If a Notice of Interest is timely delivered to
Optionor, the Optionee shall be entitled, for the next following sixty (60) day period (the
“Inspection Period”), to inspect the Option Property during normal business hours (i.e. Monday
through Friday from 9:00 a.m. to 5:00 p.m. – federal holidays excepted) upon prior notice to
Optionor of at least one (1) business day, to enter, or cause its agents or representatives to
enter, upon the Option Property for the purpose of making surveys, tests, test borings,
inspections, investigations and architectural, structural, economic, environmental and other
studies of the Option Property and tenant interviews as the Optionee may deem desirable. The
Optionee may also use the Inspection Period for obtaining title reports, surveys and/or zoning
reports. The Optionor agrees that it shall reasonably cooperate with the Optionee in connection
with any other information regarding the Option Property reasonably requested by the Optionee and
will make available such information during the Inspection Period. The Optionee shall, at the
Optionee’s sole cost and expense, promptly and fully restore any damage or destruction to the
Option Property occurring as a result of any act or omission of the Optionee by reason of such
tests, studies or investigations. The Optionee shall indemnify, defend and hold the Optionor
harmless from and against all loss, cost, damage or claim (including reasonable attorneys’ fees and
courts costs) arising out of or resulting from the Optionee’s exercise of the right and privilege
granted to the Optionee to inspect the Option Property, and the indemnity contained in this
paragraph shall survive the termination of this Option Agreement and termination of the SCP
Purchase Agreement (defined below).

(b) If, during the Inspection Period, the Optionee in its sole discretion determines that the
Option Property condition or any circumstance related to the Option Property has changed adversely
since the date of execution of this Option Agreement, or if for any or no reason whatsoever the
Optionee is not satisfied with the results of its investigations, the Optionee shall have no right
or recourse against the Optionor or the Option Property other than the right to elect not to
exercise the Option. If the Optionee determines in its sole discretion that it shall exercise the
Option, the Optionee shall provide notice of exercise to the Optionor pursuant to Section 7 below
(the “Notice of Exercise”) no later than the last day of the Inspection Period (the “Exercise
Deadline”). The date of such exercise shall be hereinafter referred to as the “Exercise Date.” On
such Exercise Date, in addition to providing the Notice of Exercise, the Optionee shall deliver to
the Optionor, in duplicate executed originals, a Purchase and Sale Agreement (the “SCP Purchase
Agreement”) for the Option Property in substantially the form attached hereto as Exhibit B

[Form to be agreed to by the parties in good faith, consistent with the following parameters,
prior to the Closing date under the SCC Purchase Agreements. The SCP Purchase Agreement shall be
similar in form and content to the SCC Purchase Agreements, excepting (i) change in price to the
Purchase Price hereunder; (ii) change in Deposit amount, prorating the deposit to reflect the same
percentage of purchase price as in the SCC Purchase Agreements; (iii) any factual changes necessary
to make the representations and warranties accurate; (iv) eliminating the inspection provision
(Section 4); (v) eliminating, or modifying as appropriate to conform to differing facts, all terms
related to existing indebtedness and debt assumption (in recognition that Optionor shall deliver
the Option Property free and clear of all mortgages); (vi) eliminating Seller’s obligation to pay
any survey costs incurred by Purchaser; (vii) eliminating non-compete terms; (viii) setting the
closing date for sixty (60) days after the Exercise Date (unless the parties agree to an earlier
date); (ix) eliminating the Battelle holdback, (x) prorating the representation and warranty escrow
to reflect the same percentage of purchase price as in the SCC Purchase Agreements, (xi) as to SPC
III, if unimproved, eliminating any provisions related to or arising from the existence of
improvements and tenants, and (xii) making other such changes as are necessary to conform the
agreement to the differing facts specific to the Option Property and not shared with any SCC
Property.]

The Optionor shall execute and return the SCP Purchase Agreement to the Optionee no later than
five (5) business days thereafter. Optionor’s failure to so execute the SCP Purchase Agreement
shall not in any manner affect Optionee’s Option rights hereunder, provided that Optionee is not in
default hereunder and Optionee’s execution and delivery of the SCP Purchase Agreement to Optionor
was in accordance with the terms hereof in all material respects. Failure of the Optionee to
deliver the Notice of Exercise by the Exercise Deadline and/or to include a signed SCP Purchase
Agreement with the Notice of Exercise, as provided above, shall render this Option Agreement null
and void, in which event neither party shall have any further obligation to the other hereunder.

(c) The Optionee agrees that it will have no rights whatsoever with respect to the Property,
its management or its operation except as expressly set forth hereunder or as expressly set forth
in the SCP Purchase Agreement after its full execution and delivery in accordance herewith.

6. Purchase Price.

(a) The purchase price for the Option Property and all other terms and conditions of the sale
and purchase of the Option Property by Optionor to Optionee (or its permitted assignee) shall be as
set forth in the SCP Purchase Agreement. The parties agree that the SCP Purchase Agreement shall
set forth the purchase price for the Option Property, which shall be calculated separately for each
of the Buildings and for SCP III, as follows. If either or both of the Buildings is one hundred
percent (100%) occupied at the time the Option is exercised, the purchase price for each such one
hundred percent (100%) occupied Building shall be equal to the result of the projected forward
twelve (12) month net operating income, based on executed leases in such building, less a five
percent (5%) general vacancy allowance applied to non-credit tenants, divided by a capitalization
rate of 8.25%. In the event that the Option is exercised with respect to the Buildings at such
time as either or both of the Buildings is not one hundred percent (100%) occupied, but is at least
fifty percent (50%) occupied, the purchase price for such partially occupied Building shall be
determined by (i) “grossing-up” the Building’s actual annual lease revenue to reflect an
eighty-five percent (85%) leased Building, (ii) subtracting actual annualized operating expenses
for the Building with operating expenses that vary with occupancy being “grossed-up” to reflect an
eighty-five percent (85%) occupied Building, (iii) deducting Thirty Dollars ($30.00) per rentable
square foot for each square foot of unleased rentable area in the Building (to cover estimated
leasing commissions and tenant improvements expenses), and (iv) applying an eight and
twenty-five/100 percent (8.25%) capitalization rate to the sum of item (i) less items (ii)
and (iii). In light of the foregoing purchase price methodology, Optionee may not exercise the
Option as to the Buildings at any time that a Building is less than fifty percent (50%) leased;
recognizing, however, that this Option Agreement shall otherwise be in full force during the entire
Option Term. The purchase price for SCP III shall, at all times during the Option Term, be Three
Million Five Hundred Thousand Dollars ($3,500,000.00).

(b) The purchase price for SCP III as aforesaid is premised on an unimproved pad site. As of
the date hereof, Optionor has no specific plans to develop SCP III. However, if Optionor decides
to construct improvements on SCP III during the Option Term, then, so long as Optionor has provided
written notice of the impending construction on SCP III at least sixty (60) days prior to the
commencement of construction but no more than one hundred eighty (180) days prior to the
commencement of construction, the purchase price for any office building that may be constructed on
SCP III, at such time thereafter and during the Option Term as such office building may become
complete and at least fifty percent (50%) leased, shall be computed in the same manner as the
purchase price for the Buildings as described in Paragraph 6(a) above (but any residential building
which may be constructed on SCP III shall not be subject to the Option). The purpose of the notice
requirement set forth in the preceding sentence is to afford Optionee the opportunity to exercise
its Option prior to the start of construction. If Optionee does not submit a Notice of Interest
within thirty (30) days of receipt of such notice from Optionor of the impending construction,
Optionor shall be free to construct improvements at will on SCP III, subject only to Optionee’s
continued Option rights during the Option Term with respect to office improvements as described
above. If Optionee does submit a Notice of Interest within thirty (30) days of receipt of such
notice from Optionor of impending construction, Optionor shall not commence construction on SCP III
and, if Optionee thereafter delivers a Notice of Exercise by the Exercise Deadline and otherwise
exercises the Option for SCP III in accordance with the requirements described above, the purchase
price for SCP III shall remain Three Million Five Hundred Thousand Dollars ($3,500,000.00). If
Optionee thereafter does not deliver a Notice of Exercise by the Exercise Deadline and/or does not
otherwise exercise the Option for SCP III in accordance with the requirements described above,
Optionor shall be free to commence construction and the Option for SCP III shall terminate and be
of no further force or effect.

7. Notice. Notices and other communications hereunder shall be given to the Optionor
(with copies as specified) and to the Optionee (with copies as specified) to the same addresses as
are set forth in Section 14.13 of the SCC Purchase Agreements, all such addresses being
incorporated herein by this reference. Such addresses may be changed from time to time by any
party by notice to the other in accordance with this Section 7. All notices and other
communications shall be effective upon receipt or refusal thereof. All notices and other
communications hereunder shall be in writing and shall be either (i) personally delivered,
(ii) sent by prepaid Federal Express or other recognized overnight delivery service, or (iii) sent
by facsimile transmission.

8. Time of Essence. Time shall be of the essence in the performance of the terms and
conditions of this Option Agreement.

9. Assignment. The Optionor may not assign this Option Agreement. The Optionee may not
assign this Option Agreement to any person, other than a direct or indirect subsidiary of Optionee
or any other entity that becomes the purchaser under the SCC Purchase Agreements, without the prior
written consent of Optionor, which consent shall not be unreasonably withheld, conditioned or
delayed. In the event of an assignment to a direct or indirect subsidiary of Optionee, Optionee
shall remain liable for the performance of the obligations of Optionee hereunder, unless and until
expressly released by Optionor. This Option Agreement shall run with the land and be binding upon
Optionor’s successors and assigns in ownership of the Property.

10. Waiver. No waiver of any breach of any covenant or agreement herein contained shall be
construed to be a waiver of the covenant or agreement itself, or of the subsequent breach thereof.
Further, no condition, obligation or provision of this Option Agreement shall be deemed to be
abrogated or waived by reason of any failures to enforce the same.

11. Completeness and Modification. This Option Agreement, together with all exhibits
hereto, constitutes the entire agreement between the parties hereto with respect to the
transactions contemplated herein, and it supersedes all prior discussions, understandings or
agreements between the parties. This Option Agreement shall not be modified or amended except by
an instrument or writing signed by both Optionor and Optionee.

12. Governing Law. This Option Agreement shall be governed by and construed in accordance
with the laws of the Commonwealth of Virginia.

13. Counterparts. To facilitate execution, this Option Agreement may be executed in
multiple counterparts, which collectively shall constitute a single instrument.

14. Recordation. Optionor and Optionee shall execute and deliver on the Closing Date under
the SCC Purchase Agreements a Memorandum of Option in the form attached hereto as Exhibit
B, which shall be recorded against the Property (at Optionee’s sole cost and expense) to
evidence Optionee’s rights hereunder. In addition, Optionor and Optionee shall execute a
Termination of Memorandum of Option in the form attached as Exhibit C, which shall be held
by Optionor’s legal counsel (the “Option Release Agent”). The Option Release Agent shall be and
hereby is authorized and instructed, without further notice or instruction or any kind from
Optionee or any other person, to record the Termination of Memorandum of Option against the
Property if any of the following shall occur: (a) the Optionee does not deliver a Notice of
Interest in accordance with the terms hereof by the Option Notice Deadline, (b) the Optionee timely
delivers a Notice of Interest but does not deliver a Notice of Exercise and a signed SCP Purchase
Agreement by the Exercise Deadline, or (c) the Optionee timely delivers a Notice of Exercise and
signed SCP Purchase Agreement but closing under the SCP Purchase Agreement has not occurred for any
reason by the thirtieth (30th) day after the closing date specified thereunder unless by
such thirtieth (30th) day the Option Release Agent has received a written notice from
Optionee stating that Optionor has defaulted under the SCP Purchase Agreement and that Optionee
will seek to specifically enforce its interest in the Option Property thereunder.

IN WITNESS WHEREOF, the parties hereto have caused this Option Agreement to be executed and
intend to be legally bound on the day and year first above written.

	 
	 

	OPTIONOR:

	STAFFORD COMMERCE PARK, L.L.C., a Virginia limited liability company

By:     

Name:

	Title:

OPTIONEE:

COLUMBIA EQUITY TRUST, INC., a Maryland corporation

By:      

Name:

9

Title:Exhibit A to Option Agreement

10

11

Legal Description of Property

[to be inserted]

Exhibit B to Option Agreement

Form of Memorandum of Option

[to be inserted]

Exhibit C to Option Agreement

Form of Termination of Memorandum of Option

[to be inserted]

12

13

EXHIBIT G

EXHIBIT H

Reps and Warranties Escrow Agreement

HOLDBACK ESCROW AGREEMENT

 This Holdback Escrow Agreement (this “Agreement”) is entered into as of      ,
2006, by and among STAFFORD COMMERCE CENTER      , L.L.C., a Virginia limited liability company
(“Seller”),      LLC, a      limited liability company (“Purchaser”), and
     , a      (the “Escrow Agent”).

WHEREAS, Seller and Purchaser’s predecessor-in-interest, Columbia Equity Trust, Inc., have
entered into that certain Purchase and Sale Agreement dated as of      , 2006 (the “Purchase
Agreement”), pursuant to which Purchaser has agreed to purchase and Seller has agreed to sell
certain Property (as defined in the Purchase Agreement); and

WHEREAS, pursuant to the Purchase Agreement, Seller has made certain representations and
warranties which survive until the one (1) year anniversary of the Closing Date (the “Termination
Date”); and

WHEREAS, to secure Purchaser in the event of a claim of breach of the representations and
warranties under the Purchase Agreement and under the Related Contracts (as defined in the Purchase
Agreement), Purchaser and Seller have agreed that an aggregate amount equal to Seven Hundred Fifty
Thousand and Zero/100 Dollars ($750,000.00) of the combined purchase prices under the Purchase
Agreement and the Related Contracts (the “Holdback Amount”) will be escrowed at Closing and held by
an escrow agent to be disbursed as provided in this Agreement; and

WHEREAS, the parties have further agreed that if the Holdback Amount is not required to
satisfy any such claims, the balance of the Holdback Amount shall be paid by the Escrow Agent to
Seller; and

WHEREAS, the Escrow Agent has agreed to act as Escrow Agent hereunder in accordance with the
terms and conditions hereinafter set forth.

NOW, THEREFORE, in consideration of the foregoing recitals and the mutual covenants,
warranties, representations and conditions contained in this Agreement, it is hereby agreed as
follows:

1. Appointment of Escrow Agent. Purchaser and Seller mutually appoint and designate
the Escrow Agent as Escrow Agent to receive, hold and disburse the Holdback Amount, and the Escrow
Agent hereby accepts such appointment and designation.

2. Establishment of Escrow. Purchaser shall deposit the Holdback Amount with the
Escrow Agent at Closing (as defined in the Purchase Agreement) and the Escrow Agent shall
acknowledge receipt of the Holdback Amount to be held in escrow in accordance with this Agreement.
The Holdback Amount shall be segregated from other assets of the Escrow Agent. The Escrow Agent
agrees to hold and administer the Holdback Amount subject to the terms of this Agreement.

3. Investment of Holdback Amount. The Escrow Agent shall invest the Holdback Amount
in direct, short-term obligations of the United States Government or its instrumentalities. All
accumulated income shall be held for the benefit of Seller and shall be paid to Seller on the
Termination Date and at the time of the final distribution of the Holdback Amount hereunder.

4. Payments from Holdback Amount; Actions on Escrow Assets.

4.1 Notice of Claims. At any time or times subsequent to the Closing Date (as such
term is defined in the Purchase Agreement) and prior to the Termination Date, Purchaser may make
claims against the Holdback Amount for payment of any loss, cost, liability, damage or expense
incurred by Purchaser arising or resulting from a breach by Seller of any of its representations or
warranties set forth in Section 3 of the Purchase Agreement. Any such claim shall be made by
Purchaser by giving written notice to Seller and Escrow Agent specifying in reasonable detail the
amount claimed and including reasonable supporting documentation (a “Notice of Claim”).

4.2 Accepted Claims. If Seller shall dispute such claim (or a portion thereof) (a
“Disputed Claim”), it shall give written notice of such objection to the Escrow Agent and Purchaser
at any time within ten (10) business days after Purchaser’s Notice of Claim (a “Dispute Notice”).
If Seller fails to give a Dispute Notice within such time period, Seller shall be deemed to have
approved the claim as a valid claim in the full amount thereof (an “Accepted Claim”). All such
notices shall be delivered as provided in Section 11 hereof.

4.3 Disputed Claims. If Seller shall dispute a claim (or portion thereof) of
Purchaser as above provided, then the Escrow Agent shall retain all or such portion of the Holdback
Amount as may be sufficient to pay said Disputed Claim in full and shall make no distribution
thereof (except for the amount of any Accepted Claim as set forth above) unless and until the
Escrow Agent receives joint written instructions from Purchaser and Seller or until there is a
final court order indicating the amount and recipient of such distribution, at which point such
Disputed Claim shall be deemed an “Accepted Claim” for purposes of this Agreement. Escrow Agent
will have the right, upon at least five (5) business days’ prior written notice to Seller and
Purchaser, to deposit the amount of any Disputed Claim into a court of competent jurisdiction for
disposition by such court pursuant to the terms hereof.

5. Release and Termination of Escrow. This Agreement shall terminate on the
Termination Date, and on the Termination Date the Holdback Amount (and interest thereon) then held
by Escrow Agent will be promptly distributed to or at the direction of Seller; provided, however,
that if the Escrow Agent has received any Notices of Claim pursuant to Section 4 of this Agreement
prior to the Termination Date which have not been resolved on the Termination Date, this Agreement
shall continue in effect until all such claims shall have been resolved. In such event, as of the
Termination Date, an amount adequate to cover the sum of amounts specified as subject to claims in
all Notices of Claim received by the Escrow Agent prior to the Termination Date and which have not
been paid or otherwise resolved will continue to be held by the Escrow Agent until they become
Accepted Claims under Section 4 above, and the Escrow Agent shall distribute the balance of the
Holdback Amount, if any, to Seller within five (5) days after the Termination Date. At such time
as all such remaining claims outstanding as of the Termination Date have been paid or otherwise
resolved pursuant to Section 4, the Escrow Agent shall distribute the remainder of the Holdback
Amount, if any, plus all interest thereon, to or as directed by Seller.

6. Duties and Responsibilities of the Escrow Agent.

6.1 No Liability. Neither the Escrow Agent nor any of its directors, officers or
employees shall be liable to anyone for any action taken or omitted to be taken by it or any of its
directors, officers, or employees hereunder except in the case of gross negligence, bad faith or
willful misconduct.

6.2 Fees. Purchaser and Seller each agree to share equally the Escrow Agent’s
reasonable compensation for its normal services hereunder (if any). Notwithstanding the previous
sentence, in the event the Escrow Agent is Walker Title Company, Seller shall be solely responsible
for all fees and charges of Escrow Agent for its services hereunder.

7. Successor Escrow Agent. Any successor Escrow Agent shall be bound by all of the
provisions hereof, and the term “Escrow Agent” as used herein shall include such a successor Escrow
Agent. The Escrow Agent may be removed at any time by joint agreement of the parties. If the
Escrow Agent resigns, it shall give thirty (30) days prior notice of resignation to Purchaser and
Seller and the parties will jointly appoint a successor Escrow Agent.

8. Accounting. In the event of the resignation or removal of the Escrow Agent, upon
the termination of the escrow hereunder, upon the termination of this Agreement or upon written
request by either Purchaser or Seller under reasonable circumstances, the Escrow Agent shall render
to Purchaser and Seller and to the successor Escrow Agent, if any, a written accounting of the
Holdback Amount any and all distributions thereof.

9. Assignability. This Agreement may not be assigned by any party. Notwithstanding
the foregoing, however, that Purchaser may assign this Agreement to any party to whom the Purchase
Agreement is being assigned in accordance with its terms. This Agreement shall inure to the
benefit of and be binding upon the parties hereto and their respective heirs, legal
representatives, successors and permitted assigns.

10. Governing Law. This Agreement shall be governed, construed and enforced in
accordance with the internal laws of the Commonwealth of Virginia, excluding any choice of law
rules which may direct the application of the laws of another jurisdiction.

11. Notices. All notices, requests, demands and other communications required or
permitted to be given hereunder shall be by hand-delivery, certified or registered mail, return
receipt requested, telecopier, or air courier to the parties set forth below. Such notices shall
be deemed given at the time personally delivered, if delivered by hand or by courier, at the time
received if sent certified or registered mail, one day after delivery to a reputable overnight
courier service, and when receipt is acknowledged by telecopy equipment, if telecopied.

	 	 	 	 	 
	If to Seller:
	 	Stafford Commerce Center, L.L.C.

	 
	 	? Garrett Development Corporation
	 
	 	25 Center Street, Suite 101
	 
	 	Stafford, Virginia 22556

	 
	 	Attention:   Andrew S. Garrett

	 
	 	Telecopier:  (540) 659-3449

	with a copy to:
	 	Foley Hoag LLP

	 
	 	1875 K Street, N.W., Suite 800
	 
	 	Washington, D.C. 20006

	 
	 	Attention:  Stephanie Cutler, Esq.

	 
	 	Telecopier:  (202) 467-9630

	If to Purchaser:
	 	 	—	 
	 
	 	? Columbia Equity Trust, Inc.
	 
	 	1750 H Street, N.W., Suite 500
	 
	 	Washington, D.C.

	 
	 	Attention:  Clinton D. Fisch

	 
	 	Telecopier:  (202) 303-3088

	with a copy to:
	 	Watt Tieder Hoffar & Fitzgerald, L.L.P.

	 
	 	8405 Greensboro Drive, Suite 100
	 
	 	McLean, Virginia 22012

	 
	 	Attention:  Colin J. Smith, Esq.

	 
	 	Telecopier:  (703) 749-0479

	If to Escrow Agent:
	 	 	—	 

     

     

Attention:     

Telecopier:      

Notwithstanding the foregoing, a Notice of Claim under Section 4.1 above must be sent to Seller and
Seller’s counsel set forth above by an authorized method of delivery under this Section 11 other
than telecopier.

12. Counterparts. This Agreement may be executed in multiple counterparts, each which
shall be an original, but all of which together shall constitute one and the same agreement.

13. Modifications. This Agreement may not be altered or modified without the express
written consent of the parties hereto.

14. Entire Agreement, Severability and Further Assurances. This Agreement together
with all schedules hereto constitutes the entire agreement among the parties, and all promises,
representations, undertakings, warranties and agreements with reference to the subject matter
hereof and inducements to the making of this Agreement relied upon by any party hereto, have been
expressed herein or in the documents incorporated herein by reference.

IN WITNESS WHEREOF, the parties have executed this Agreement or caused the same to be executed
by their duly authorized representatives as of the date first stated hereinabove.

PURCHASER:

     , LLC, a      limited liability
company

By:      

Name:

Title:

	 	 	 	 	 	 	 	 	 
	SELLER:
	 	 	 	 	 	 	 	 
	 

	STAFFORD COMMERCE CENTER ___, L.L.C., a Virginia limited liability company

	By:	 	Garrett Development Corporation, Its Manager

	 
	 	By:
	 	 	—	 
	 
	 	 	 	 	 	Andrew S. Garrett, President

	By:	 	Cutler Development Corporation, Its Manager

	 
	 	By:
	 	 	—	 
	 
	 	 	 	 	 	Miriam J. Cutler, President

Receipt of original copies of this Agreement executed by Purchaser and Seller is acknowledged
this      day of      , 2006. Escrow Agent expressly acknowledges and agrees to comply with
the provisions hereof governing the holding and disposition of the Deposit, including without
limitation Section      herein.

ESCROW AGENT:

By:

Name:     

Title:     

14

EXHIBIT I

Form of CC&R Estoppel Certificate

Columbia Equity Trust, Inc.

1750 H Street, N.W., Suite 500

Washington, DC 20006

Attn: Mr. Clinton D. Fisch

	 	 	 	Re: Declaration for Stafford Commerce Center dated November 7, 2001 and recorded among the
land records of Stafford County, Virginia (the “Land Records”) as Instrument 1 LR010026943
(the “Declaration”)

Ladies and Gentlemen:

You have informed us of a pending sale of the property located at 25 Center Street, Stafford,
Virginia (the “Property”). For Ten and Zero/100 Dollars ($10.00) and other good and sufficient
consideration, receipt of which is hereby acknowledged, and for the purposes of providing
information to Columbia Equity Trust, Inc., a Maryland corporation (together with its successors
and assigns, the “Purchaser”) and to Purchaser’s mortgage lender (together with its successors and
assigns, the “Lender”) regarding the Property and the Declaration, the undersigned (the
“Undersigned”) does hereby certify to Purchaser and Lender and agree that:

	 	1.	 	The Declaration is in full force and effect, and is valid and enforceable
according to its terms and has not been modified, amended, supplemented or changed in
any respect.

	 	2.	 	As of the date hereof, all assessments, common expenses or other payments due
from Stafford Commerce Center, L.L.C., a Virginia limited liability company (“Seller”),
as the current owner of the Property, under the Declaration and with respect to the
Property have been paid as of the date of this certification.

	 	3.	 	Neither Seller, as current owner of the Property, the Property or the
Undersigned is in default in any material respect under the Declaration, nor has any
event occurred, which with the passage of time or the giving of notice, would
constitute a material default under the Declaration.

	 	4.	 	As of the date hereof, no notices of regular or special assessments have been
issued to Seller under the Declaration which remain unpaid as of the date of this
certification.

	 	5.	 	This certification may not be changed, waived or discharged orally, but only by
an agreement in writing.

IN WITNESS WHEREOF, the Undersigned has caused this certificate to be executed as of the      
day of      2006.

Stafford Commerce Center Owners Association,
a Virginia non-stock corporation

By:      

Andrew S. Garrett, President

15

AGREEMENT OF PURCHASE AND SALE

Between

STAFFORD COMMERCE CENTER, L.L.C.

“Seller”

and

COLUMBIA EQUITY TRUST, INC.

“Purchaser”

16

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00107-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00107-of-00352.parquet"}]]