Designated Filer: Warburg Pincus Private Equity IX, L.P.

Issuer & Ticker Symbol: Builders FirstSource, Inc. (BLDR)

Date of Event Requiring Statement: June 7, 2012

JOINT FILERS’ SIGNATURES

	WARBURG PINCUS IX  LLC
	By:  Warburg Pincus Partners LLC, its Sole Member,      By:  Warburg Pincus & Co., its Managing Member
	By:  /s/ Scott A. Arenare	Date: June 11, 2012
	Name:  Scott A. Arenare Title:  Partner
	WARBURG PINCUS PARTNERS LLC
	By:  Warburg Pincus & Co., its Managing Member
	By:  /s/ Scott A. Arenare	Date: June 11, 2012
	Name:  Scott A. Arenare Title:  Partner
	WARBURG PINCUS LLC
	By:  /s/ Scott A. Arenare	Date: June 11, 2012
	Name:  Scott A. Arenare Title:  Managing Director
	WARBURG PINCUS & CO.
	By:  /s/ Scott A. Arenare	Date: June 11, 2012
	Name:  Scott A. Arenare Title:  Partner
	CHARLES R. KAYE
	By:  /s/ Scott A. Arenare	Date: June 11, 2012
	Name:  Charles R. Kaye By:  Scott A. Arenare, Attorney-in-Fact*
	JOSEPH P. LANDY
	By:  /s/ Scott A. Arenare	Date: June 11, 2012
	Name:  Joseph P. Landy By:  Scott A. Arenare, Attorney-in-Fact*

* The Power of Attorney given by Mr. Kaye and Mr. Landy was previously filed with the U.S. Securities and Exchange Commission on March 2, 2006 as an exhibit to a statement on Schedule 13D filed by Buildings Products, LLC with respect to Builders FirstSource, Inc. and is hereby incorporated by reference.