The term "building envelope" typically refers to the exterior surface of a building's construction—the foundation, roof, walls, windows and everything that connects them together—including all aspects of the building's exterior design that impact energy costs. Canam's consulting and contracting services business focuses on evaluating the energy efficiency of building envelopes and reducing energy costs through better air sealing and air barriers, including new construction and retrofit contracting work, design consultation, field-testing and installation. Zerodraft provides specialized retrofit weatherstripping and distributes a variety of related insulation and sealant products.