Cornerstone Building Brands, Inc.

Cornerstone Building Brands, Inc. is North America's largest manufacturer of exterior building products, serving both residential and commercial customers in new construction and repair & remodel markets. The company's purpose is to provide building solutions that form the cornerstone of communities where people live, work, and play, aiming to be the premier solutions company that better serves its customers and builds stronger communities. Its headquarters are located in Cary, North Carolina, USA.

The company offers a comprehensive portfolio of products, including windows, vinyl siding and accessories, metal roofing and components, insulated metal panels, metal wall systems, engineered commercial buildings, stone veneer, entry doors, cellular PVC trim, vinyl fencing and railing, gutter, and metal accessories. Key brands under its umbrella include Ply Gem, Simonton, Atrium, Mueller, and MBCI, among others. These products cater to a wide range of applications, from single-family homes and multi-family developments to commercial offices, healthcare facilities, and industrial buildings.

As of July 2022, Cornerstone Building Brands became a privately held company following its acquisition by affiliates of Clayton, Dubilier & Rice (CD&R), and its stock ceased trading on the New York Stock Exchange. Gunner Smith was appointed CEO effective August 11, 2025. Recent developments include the appointment of Austin So as Executive Vice President, General Counsel and Corporate Secretary in July 2026, the celebration of the MBCI® brand's 50th anniversary in June 2026, and the unification of its metal solutions retail network under the Mueller™ brand in May 2026. The company also expanded its residential metal roofing portfolio through the acquisition of Union Corrugating Company.