EX-4.1



 Exhibit 4.1 
 AMENDMENT NO. 15 
 TO THE 

AMENDED AND RESTATED LIMITED PARTNERSHIP AGREEMENT OF 
 FIRST POTOMAC REALTY INVESTMENT LIMITED PARTNERSHIP 
 This Amendment No. 15
(the “Fifteenth Amendment”) to the Amended and Restated Limited Partnership Agreement of First Potomac Realty Investment Limited Partnership (the “Partnership”) dated September 15, 2003 (the “Partnership
Agreement”), is entered into as of March 25, 2011, by First Potomac Realty Trust, the general partner (the “General Partner”) of the Partnership, and the Members of 840 First Street LLC, Stephen A. Goldberg, Brian L. Goldberg
Generational Trust, Lauren B. Goldberg Generational Trust and Stuart W. Goldberg Generational Trust (collectively, the “Contributors”). All capitalized terms used herein and not otherwise defined shall have the meanings assigned to them in
the Partnership Agreement. 
 WHEREAS, pursuant to the terms of that certain Contribution Agreement, dated as of
November 2, 2010 by and among 840 First Street LLC and the Partnership (the “Contribution Agreement”), the Contributors have agreed to contribute to the Partnership the property commonly known as 840 First Street, NE located in
Washington, DC, in exchange for limited partnership operating units in the Partnership; 
 WHEREAS, it is desirable to amend
Exhibit A to the Partnership Agreement to reflect the Contributors’ admission to the Partnership; 
 NOW, THEREFORE, for
good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Partnership Agreement is hereby amended as follows: 
 Exhibit A to the Partnership Agreement is hereby amended by substituting for the current version of such exhibit, a version in the form attached hereto as Exhibit A reflecting the admission of the
Contributors to the Partnership, subject to the provisions contained in the Contribution Agreement. 
 IN WITNESS WHEREOF, the
foregoing Fifteenth Amendment has been signed and delivered as of this 25th day of March, 2011, by the parties set forth above. 
  

			
	 FIRST POTOMAC REALTY TRUST,
 General Partner

		
	By:	 	/s/ Joel F. Bonder
		 	     Joel F. Bonder
     Executive Vice President










 Limited Partner Acceptance 

March 25, 2011 
 This Limited Partner Acceptance (the “Acceptance”) to the Amended and Restated Agreement of Limited Partnership, as amended to the date hereof, of First Potomac Realty Investment Limited
Partnership, L.P. (the “Partnership Agreement”), which Acceptance is entered into in connection with the Partnership Agreement, is executed and delivered by the undersigned. As of the date hereof, the undersigned General Partner
hereby admits the undersigned Limited Partner as a Limited Partner of the Partnership, and by said undersigned Limited Partner’s execution and delivery hereof, said undersigned Limited Partner agrees to be bound by the terms and provisions of
the Partnership Agreement, including the power of attorney set forth in Section 8.02 of the Partnership Agreement. The number of units of limited partnership interest (“Units”) issued as of the date hereof to the undersigned
Limited Partner is set forth below. All terms used herein and not otherwise defined shall have the meanings given them in the Partnership Agreement. 
 Number of Units: 993,102 
 [Signature Page follows] 







 
	
	ADDITIONAL LIMITED PARTNER:
	
	/s/ Stephen A. Goldberg
	Stephen A. Goldberg


 [End of Signatures] 
 Limited Partner Acceptance – Stephen A. Goldberg 







 Limited Partner Acceptance 

March 25, 2011 
 This Limited Partner Acceptance (the “Acceptance”) to the Amended and Restated Agreement of Limited Partnership, as amended to the date hereof, of First Potomac Realty Investment Limited
Partnership, L.P. (the “Partnership Agreement”), which Acceptance is entered into in connection with the Partnership Agreement, is executed and delivered by the undersigned. As of the date hereof, the undersigned General Partner
hereby admits the undersigned Limited Partner as a Limited Partner of the Partnership, and by said undersigned Limited Partner’s execution and delivery hereof, said undersigned Limited Partner agrees to be bound by the terms and provisions of
the Partnership Agreement, including the power of attorney set forth in Section 8.02 of the Partnership Agreement. The number of units of limited partnership interest (“Units”) issued as of the date hereof to the undersigned
Limited Partner is set forth below. All terms used herein and not otherwise defined shall have the meanings given them in the Partnership Agreement. 
 Number of Units: 141,871 
 [Signature Page follows] 







 
	
	 ADDITIONAL LIMITED PARTNER:
  

BRIAN L. GOLDBERG GENERATIONAL TRUST

	
	/s/ Diana L. Goldberg
	 Diana L. Goldberg, Trustee

U/A dated January 2, 2002 for the
 Brian L.
Goldberg Generational Trust

	
	/s/ Martin J. Kirsch
	 Martin J. Kirsch, Trustee

U/A dated January 2, 2002 for the
 Brian L.
Goldberg Generational Trust



 [End of Signatures] 
 Limited Partner Acceptance – Brian L. Goldberg Generational Trust 







 Limited Partner Acceptance 

March 25, 2011 
 This Limited Partner Acceptance (the “Acceptance”) to the Amended and Restated Agreement of Limited Partnership, as amended to the date hereof, of First Potomac Realty Investment Limited
Partnership, L.P. (the “Partnership Agreement”), which Acceptance is entered into in connection with the Partnership Agreement, is executed and delivered by the undersigned. As of the date hereof, the undersigned General Partner
hereby admits the undersigned Limited Partner as a Limited Partner of the Partnership, and by said undersigned Limited Partner’s execution and delivery hereof, said undersigned Limited Partner agrees to be bound by the terms and provisions of
the Partnership Agreement, including the power of attorney set forth in Section 8.02 of the Partnership Agreement. The number of units of limited partnership interest (“Units”) issued as of the date hereof to the undersigned
Limited Partner is set forth below. All terms used herein and not otherwise defined shall have the meanings given them in the Partnership Agreement. 
 Number of Units: 141,871 
 [Signature Page follows] 







 
	
	 ADDITIONAL LIMITED PARTNER:
  

LAUREN B. GOLDBERG GENERATIONAL TRUST

	
	/s/ Diana L. Goldberg
	 Diana L. Goldberg, Trustee

U/A dated January 2, 2002 for the
 Lauren B.
Goldberg Generational Trust

	
	/s/ Martin J. Kirsch
	 Martin. J. Kirsch, Trustee

U/A dated January 2, 2002 for the
 Lauren B.
Goldberg Generational Trust



 [End of Signatures] 
 Limited Partner Acceptance – Lauren B. Goldberg Generational Trust 







 Limited Partner Acceptance 

March 25, 2011 
 This Limited Partner Acceptance (the “Acceptance”) to the Amended and Restated Agreement of Limited Partnership, as amended to the date hereof, of First Potomac Realty Investment Limited
Partnership, L.P. (the “Partnership Agreement”), which Acceptance is entered into in connection with the Partnership Agreement, is executed and delivered by the undersigned. As of the date hereof, the undersigned General Partner
hereby admits the undersigned Limited Partner as a Limited Partner of the Partnership, and by said undersigned Limited Partner’s execution and delivery hereof, said undersigned Limited Partner agrees to be bound by the terms and provisions of
the Partnership Agreement, including the power of attorney set forth in Section 8.02 of the Partnership Agreement. The number of units of limited partnership interest (“Units”) issued as of the date hereof to the undersigned
Limited Partner is set forth below. All terms used herein and not otherwise defined shall have the meanings given them in the Partnership Agreement. 
 Number of Units: 141,871 
 [Signature Page follows] 







 
	
	 ADDITIONAL LIMITED PARTNER:
  

STUART W. GOLDBERG GENERATIONAL TRUST

	
	/s/ Diana L. Goldberg
	 Diana L. Goldberg, Trustee

U/A dated January 2, 2002 for the
 Stuart W.
Goldberg Generational Trust

	
	/s/ Martin J. Kirsch
	 Martin. J. Kirsch, Trustee

U/A dated January 2, 2002 for the
 Stuart W.
Goldberg Generational Trust



 [End of Signatures] 
 Limited Partner Acceptance – Stuart W. Goldberg Generational Trust