X0306 4 2015-12-01 0 0001316835 Builders FirstSource, Inc. BLDR 0001326954 MCALEENAN DONALD F 2001 BRYAN STREET SUITE 1600 DALLAS TX 75201 0 1 0 0 SVP & General Counsel Common Stock, par value $0.01 per share 2015-12-01 4 M 0 23343 7.67 A 304577 D Common Stock, par value $0.01 per share 2015-12-01 4 M 0 36657 3.19 A 341234 D Common Stock, par value $0.01 per share 2015-12-01 4 S 0 60000 13.36 D 281234 D Common Stock, par value $0.01 per share 2015-12-02 4 M 0 4300 3.19 A 285534 D Common Stock, par value $0.01 per share 2015-12-02 4 M 0 85700 7.15 A 371234 D Common Stock, par value $0.01 per share 2015-12-02 4 S 0 90000 13.48 D 281234 D Employee Stock Option (right to buy) 7.67 2015-12-01 4 M 0 23343 0.00 D 2024-02-11 Common Stock 23343 70032 D Employee Stock Option (right to buy) 3.19 2015-12-01 4 M 0 36657 0.00 D 2020-02-03 Common Stock 36657 198343 D Employee Stock Option (right to buy) 3.19 2015-12-02 4 M 0 4300 0.00 D 2020-02-03 Common Stock 4300 194043 D Employee Stock Option (right to buy) 7.15 2015-12-02 4 M 0 85700 0.00 D 2018-05-22 Common Stock 85700 0 D This transaction was executed in multiple trades at prices ranging from $13.11 to $13.55 per share. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide full information regarding the number of shares and prices at which the transactions were effected upon request by the SEC staff, the issuer, or a security holder of the issuer. This transaction was executed in multiple trades at prices ranging from $13.27 to $13.64 per share. The price reported above reflects the weighted average sale price. The reporting person hereby undertakes to provide full information regarding the number of shares and prices at which the transactions were effected upon request by the SEC staff, the issuer, or a security holder of the issuer. Award issued under the Company's 2007 Incentive Plan, as amended and restated on January 14, 2010. The option was granted on February 11, 2014 and vests in 25% increments on each of February 11, 2015-2018. The option was granted on February 3, 2010 and vested in 33.33% increments on each of February 3, 2012-2014. Award issued under the Company's 2005 Incentive Plan. The option was granted on May 22, 2008 and vested in 33.3% increments on each of February 26, 2009-2011 /s/ Donald F. McAleenan 2015-12-03