Title: Building envelope - Wikipedia
Headings: Building envelope
Building envelope
Contents
Discussion
Water and water vapor control
Air control
Thermal envelope
See also
References
External links

Content: The physical components of the envelope include the foundation, roof, walls, doors, windows, ceiling, and their related barriers and insulation. The dimensions, performance and compatibility of materials, fabrication process and details, connections and interactions are the main factors that determine the effectiveness and durability of the building enclosure system. Common measures of the effectiveness of a building envelope include physical protection from weather and climate (comfort), indoor air quality (hygiene and public health), durability and energy efficiency. In order to achieve these objectives, all building enclosure systems must include a solid structure, a drainage plane, an air barrier, a thermal barrier, and may include a vapor barrier. Moisture control (e.g. damp proofing) is essential in all climates, but cold climates and hot-humid climates are especially demanding. Thermal envelope
The thermal envelope, or heat flow control layer, is part of a building envelope but may be in a different location such as in a ceiling. The difference can be illustrated by the fact that an insulated attic floor is the primary thermal control layer between the inside of the house and the exterior while the entire roof (from the surface of the roofing material to the interior paint finish on the ceiling) is part of the building envelope. Building envelope thermography involves using an infrared camera to view temperature anomalies on the interior and exterior surfaces of the structure. Analysis of infrared images can be useful in identifying moisture issues from water intrusion, or interstitial condensation. Other types of anomalies that can be detected are thermal bridging, continuity of insulation and air leakage, however this requires a temperature differential between the inside and outside ambient temperatures.