X0306 4 2019-05-22 0 0001316835 Builders FirstSource, Inc. BLDR 0001049506 CHRISTOPHE CLEVELAND A 2001 BRYAN STREET SUITE 1600 DALLAS TX 75201 1 0 0 0 Common Stock, par value $0.01 per share 2019-05-22 4 A 0 6748 0.00 A 31739 D Common Stock, par value $0.01 per share 2019-05-23 4 S 0 6000 15.22 D 25739 D Reflects the acquisition of restricted stock units pursuant to the Corporation's 2014 Incentive Plan. The restricted stock units vest on May 22, 2020 and entitle the reporting person to one share of common stock for each restricted stock unit that vests. This transaction was executed in multiple trades at prices ranging from $15.20 to $15.24 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. /s/ Jeffrey A. Wier by power of attorney 2019-05-24