Sec Form 4 Filing - JLL Building Holdings, LLC @ Builders FirstSource, Inc. - 2017-03-08

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 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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1. Name and Address of Reporting Person JLL Building Holdings, LLC 2. Issuer Name and Ticker or Trading Symbol Builders FirstSource, Inc. [ BLDR] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O JLL PARTNERS, INC., 450 LEXINGTON AVENUE, 31ST FLOOR 3. Date of Earliest Transaction (MM/DD/YY) 03/08/2017 (Street) NEW YORK, NY10017 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 03/08/2017 S 10,000,000 D $ 14.51 14,344,584 I See footnote ( 1 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other JLL Building Holdings, LLC C/O JLL PARTNERS, INC. 450 LEXINGTON AVENUE, 31ST FLOOR NEW YORK, NY10017 X JLL PARTNERS FUND V LP 450 LEXINGTON AVE, 31ST FLOOR NEW YORK, NY10017 X JLL Associates V, L.P. 450 LEXINGTON AVE, SUITE 3350 NEW YORK, NY10017 X JLL Associates G.P. V, L.L.C. 450 LEXINGTON AVE, SUITE 3350 NEW YORK, NY10017 X Signatures JLL Building Holdings, LLC, JLL Partners Fund V, L.P., JLL Associates V, L.P., JLL Associates G.P. V, L.L.C. /s/ Daniel Agroskin, Authorized Signatory of JLL Associates G.P. V, L.L.C. 03/10/2017 Signature of Reporting Person Date JLL Partners Fund V, L.P., JLL Associates V, L.P., JLL Associates G.P. V, L.L.C. /s/ Daniel Agroskin, Authorized Signatory of JLL Associates G.P. V, L.L.C. 03/10/2017 Signature of Reporting Person Date JLL Associates V, L.P., JLL Associates G.P. V, L.L.C. /s/ Daniel Agroskin, Authorized Signatory of JLL Associates G.P. V, L.L.C. 03/10/2017 Signature of Reporting Person Date JLL Associates G.P. V, L.L.C. /s/ Daniel Agroskin, Authorized Signatory 03/10/2017 Signature of Reporting Person Date

Explanation of Responses:

( 1 )This report is filed jointly by JLL Building Holdings, LLC ("JLL Holdings"); JLL Partners Fund V, L.P., the sole member of JLL Holdings; JLL Associates V, L.P., the general partner of JLL Fund V, L.P.; and JLL Associates G.P. V, L.L.C., the general partner of JLL Associates V, L.P. (the "Reporting Persons"). JLL Holdings is the direct owner of 14,344,584 shares of common stock, par value $0.01 per share, of Builders FirstSource, Inc. By reason of the provisions of Rule 16a-1 of the Securities Exchange Act of 1934, as amended (the "Exchange Act"), JLL Partners Fund V, L.P., JLL Associates V, L.P., and JLL Associates G.P. V, L.L.C. may be deemed to be the beneficial owners of any securities that may be beneficially owned by JLL Holdings. However, the foregoing Reporting Persons disclaim beneficial ownership of these securities, except to the extent of any pecuniary interest therein.

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.

* 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).

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