Building Envelope Functions and Components

The building envelope is the physical separator between the conditioned and unconditioned environment of a building, including the resistance to air, water, heat, light, and noise transfer.

The many functions of the building envelope can be separated into three categories: control of rain, air control, and heat control.

Water and water vapor control are the most fundamental functions of the building envelope.

Air control includes the control of windwashing and convective loops, which can affect building insulation performance greatly.

The physical components of the envelope include the foundation, roof, walls, doors, windows, ceiling, and their related barriers and insulation.

The building envelope is the outer covering of a structure, which helps to protect it from the weather and climate, and also provides a comfortable and healthy environment for people inside.

The building envelope must include a solid structure, a drainage plane, an air barrier, a thermal barrier, and may include a vapor barrier.

The air sealing of the building envelope can improve the energy efficiency of a building.

Thermal envelope thermography can be used to detect 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.