We are the only vinyl siding producer who is NGBS Green Certified, under 2008 NGBS green practice #604.1(2). This standard states that building materials with recycled content are used for at least 2 major components AND this product is used in conjunction with another major product with recycled content.. HVAC,HVAC Repair parts,Doors and Windows,interior Doors and Trim,Foundation Covers,Exterior Wall Coverings,Steps,Decks,and Rails,Plumbing,Electrical,Appliances,Setup and Transportation,Sealants and Adhesives,Tools and Fasteners,Specialty Window.