The “building envelope” refers to the external walls, windows, roof, and floor of a building. This barrier between indoors and outdoors is important with regards to ventilation and insulation of a conditioned space. A “tighter” envelope (i.e. one with fewer gaps through which air can flow) more effectively keeps conditioned air in, reducing the load on the HVAC system, and therefore increasing the efficiency at which it operates. Similarly, insulation helps slow the conduction of heat through walls. Improving the efficiency of the building envelope is generally a low-cost, high-return method for increasing efficiency in buildings.
Research, policies, and programs related to building envelope can be found in the links below and to the right. For specific efficiency tips and guidance on the building envelope, click here.