How is an air barrier system defined?

An air barrier system is defined as the combined assemblies making up the entire building envelope system. This definition encompasses not only the individual components but also how those components work together to create a continuous barrier against air movement. An effective air barrier system involves several materials and assemblies, including walls, roofs, windows, and any necessary sealants or flashings, all integrated to minimize air leakage and improve energy efficiency.

Understanding the air barrier as a system highlights the importance of continuity and connectivity between elements. Each component plays a vital role, but it’s the collective performance of these components that determines the overall effectiveness of the air barrier. A fragmented approach, focusing solely on individual elements or materials, would overlook critical interactions that can lead to air leaks and reduce energy performance. Therefore, thinking in terms of combined assemblies provides insight into achieving a comprehensive, functional air barrier system that is essential for maintaining comfort, controlling moisture, and enhancing overall building performance.