X0508 4 2023-09-01 0 0001316835 Builders FirstSource, Inc. BLDR 0001212607 ALEXANDER MARK A C/O BUILDERS FIRSTSOURCE, INC. 6031 CONNECTION DR., STE. 400 IRVING TX 75039 1 0 0 0 0 Common Stock, par value $0.01 per share 2023-09-01 4 A 0 210 148.74 A 39809 D Reflects acquisition of shares in lieu of cash compensation for services as a director under the Corporation's 2014 Incentive Plan pursuant to the Corporation's Amended and Restated Director Compensation Policy. /s/ Minator Azemi, by power of attorney 2023-09-06