The building envelope (building enclosure) contains a foundation, floor systems, interior and exterior walls and the roof system. It is the actual physical separators between the conditioned environment and the unconditioned, exterior environment. The envelope includes resistance to noise transfer, heat, light, air and water. The building envelope typically has a weather barrier, thermal barrier and an air barrier.
The building envelope includes all of the elements that help to maintain a dry, heated or cooled environment that helps to control climate inside the home. This specialized area seeks to support, control and finish and is what helps the overall performance of the home. Things such as control of rain and damp proofing help maintain the integrity of a home. Also, control of air flow is important as it makes sure that indoor air quality is efficient, it helps the home to avoid condensation and to control the amount of energy consumed.
In order to properly maintain an energy efficient home, it is critical that the envelope support energy retention. The envelope must include insulation and sealants to keep heat or air in as desired, yet allow some fresh air intake. A professional home inspector can properly examine all facets of your building envelope to ensure their functionality and efficiency.