What is the purpose of an air barrier in construction?

The primary purpose of an air barrier in construction is to control moisture and air movement within the building envelope. An effective air barrier helps prevent unintentional air leaks, which can result in a variety of issues such as energy loss, condensation problems, and potential mold growth. By minimizing the infiltration of outside air and the exfiltration of conditioned indoor air, the air barrier contributes significantly to maintaining indoor air quality and the overall energy efficiency of the building.

In addition to moisture control, air barriers play a critical role in managing the air pressure differences that occur due to various environmental factors and mechanical systems within the building. This management ensures that the building can perform optimally, with reduced reliance on heating and cooling systems, thereby enhancing overall sustainability.

While options related to thermal comfort, structural stability, and sound insulation are important aspects of building design, they do not encompass the primary function of an air barrier, which centers on regulating air and moisture transfer.