FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN 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 * CROW M CHAD   2. Issuer Name and Ticker or Trading Symbol Builders FirstSource, Inc. [BLDR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) VP of Finance and Controller (Last) (First) (Middle) C/O BUILDERS FIRSTSOURCE, INC, 2001 BRYAN STREET, SUITE 1600 3. Date of Earliest Transaction (Month/Day/Year) 11/01/2005 (Street) DALLAS, TX 75201 4. If Amendment, Date Original Filed(Month/Day/Year) 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 Acquired, Disposed of, or Beneficially Owned

1.Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4) Code V Amount (A) or (D) Price Common Stock, par value $0.01 per share 11/01/2005   M   8,750 A $ 3.15 0 (5) D   Common Stock, par value $0.01 per share 11/01/2005   S   8,750 D $ 19.6 0 (5) D   Common Stock, par value $0.01 per share 11/01/2005   S   8,850 D $ 19.5 0 (5) D

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)

1. Title of Derivative Security (Instr. 3)

2. Conversion or Exercise Price of Derivative Security

3. Transaction Date (Month/Day/Year)

3A. Deemed Execution Date, if any (Month/Day/Year)

4. Transaction Code (Instr. 8)

5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4, and 5)

6. Date Exercisable and Expiration Date (Month/Day/Year)

7. Title and Amount of Underlying Securities (Instr. 3 and 4)

8. Price of Derivative Security (Instr. 5)

9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)

10. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 4)

11. Nature of Indirect Beneficial Ownership (Instr. 4)

Code

V

(A)

(D)

Date Exercisable

Expiration Date

Title

Amount or Number of Shares

Employee Stock Option (right to buy)

$ 3.15

11/01/2005

M

2,500

(1)

09/27/2009

Common Stock

2,500

$ 0 (5)

0

D

Employee Stock Option (right to buy)

$ 3.15

11/01/2005

M

2,000

(2)

05/01/2010

Common Stock

2,000

$ 0 (5)

0

D

Employee Stock Option (right to buy)

$ 3.15

11/01/2005

M

4,250

(3)

02/27/2014

Common Stock

25,500

$ 0 (5)

21,250

D

Employee Stock Option (right to buy)

$ 20.8

10/25/2005

A

15,000

(4)

10/25/2015

Common Stock

15,000

$ 0 (5)

15,000

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
CROW M CHAD C/O BUILDERS FIRSTSOURCE, INC 2001 BRYAN STREET, SUITE 1600 DALLAS, TX 75201			VP of Finance and Controller

Signatures

/s/ M. Chad Crow		11/01/2005
**Signature of Reporting Person		Date

Explanation of Responses:

*	If the form is filed by more than one reporting person, see Instruction 4(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)	100% is presently exercisable. Option vested in 33.3% increments on each of September 27, 2000-2002.
(2)	100% is presently exercisable. Option vested in 20% increments on each of May 1, 2001-2005.
(3)	16.67% of this award 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.
(4)	The option vests in 33.3% increments on each of October 25, 2006-2008.
(5)	Not applicable.

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