Ownership Submission
FORM 3
 UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  HORN CHARLES L
 2. Date of Event Requiring Statement (Month/Day/Year)
06/21/2005		 3. Issuer Name and Ticker or Trading Symbol
Builders FirstSource, Inc. [BLDR]
(Last)
(First)
(Middle)
BUILDERS FIRSTSOURCE, INC., 2001 BRYAN STREET, SUITE 1600		 4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director _____ 10% Owner
__X__ Officer (give title below) _____ Other (specify below)
Sr. Vice President and CFO
 5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

DALLAS, TX 75201		 6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)		 2. Amount of Securities Beneficially Owned
(Instr. 4)		 3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)		 4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Common Stock, par value $0.01 per share 12,500
D
 

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)		 2. Date Exercisable and Expiration Date
(Month/Day/Year)		 3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)		 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)		 6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Common Stock Option 05/12/2002 05/12/2009 Common Stock, par value $0.01 per share 15,000 $ 3.15 D  
Common Stock Option 05/01/2005 05/01/2010 Common Stock, par value $0.01 per share 10,000 $ 3.15 D  
Common Stock Option   (1) 02/13/2011 Common Stock, par value $0.01 per share 10,000 $ 3.15 D  
Common Stock Option   (2) 01/16/2012 Common Stock, par value $0.01 per share 178,216 $ 3.15 D  
Common Stock Option   (3) 02/27/2014 Common Stock, par value $0.01 per share 111,783 $ 3.15 D  

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
HORN CHARLES L
BUILDERS FIRSTSOURCE, INC.
2001 BRYAN STREET, SUITE 1600
DALLAS, TX 75201		       Sr. Vice President and CFO  

Signatures

/s/ Charles L. Horn 06/21/2005
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) 80% is presently exercisable and 20% will become exercisable on 02/13/2006 should Builders FirstSource, Inc. (the "Company") meet certain financial targets. However, regardless of whether the Company meets its financial targets, the option will be fully exercisable on 02/13/2010.
(2) 75% is presently exercisable and 25% will become exercisable on 09/01/2005.
(3) 16.67% is presently exercisable and the remainder will become exercisable in 2005 and 2006 should the Company meet certain financial targets in those years. However, regardless of whether the Company meets its financial targets, the option will be fully exercisable on 12/31/2011.

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