PUSHING THE BUILDING ENVELOPE

building materials made wholly or primarily of metal, namely, building wall framing, composite panels, cladding material for building, curtain walls, door frames and casings, doors, windows and storefronts in the nature of prefabricated walls for installation in the front of commercial establishments

architectural building glass; non-metal curtain walls, non-metal storefronts in the nature of prefabricated walls for installation in the front of commercial establishments; non-metal architectural windows, and non-metal entrance doors featuring glass