About Cornerstone Building Brands Cornerstone Building Brands is the largest manufacturer of exterior building products in North America. Headquartered in Cary, North Carolina, the organization serves residential and commercial customers across new construction and repair & remodel market. As the #1 manufacturer of windows, vinyl siding, insulated metal panels, metal roofing and wall systems and metal accessories, Cornerstone Building Brands combines a comprehensive portfolio of products with an expansive national footprint that includes more than 21,000 employees at manufacturing, distribution and office locations throughout North America. Cornerstone Building Brands operates by using a nationwide hub-and-spoke delivery program, determining the closest facility that can satisfy a project's specifications. This hub-and-spoke distribution method benefits the customer by decreasing delivery times, lowering transportation costs and reducing negative effects on the environment.