In 2012, the International Energy Conservation Code (IECC) introduced the requirement for a continuous air barrier throughout the building thermal envelope. At the time, there was little guidance on how to verify that the requirement, but with each new version of the energy code, provisions are incorporated that expand on acceptable methods for compliance and verification procedures.

One compliance path within the IECC is through ASHRAE Standard 90.1. Similar to the IECC, ASHRAE 90.1 has also progressively expanded requirements for air leakage control and verification, though the approaches differ slightly. Depending on project goals and Owner specific requirements, compliance with stretch codes, such as the International Green Construction Code (IgCC), or Passive House standards may also apply. Moreover, state and local jurisdictions can add to or modify these requirements, further affecting air leakage limits and verification methods.

As codes have evolved, there is an emphasis not only on the design of the air barrier, but also on verification during construction, including through Whole Building Air Leakage Testing. Navigating there varying compliance paths required careful coordination among design and construction teams to ensure performance requirements are met from design through completion of the project.

This session will discuss the importance of a continuous air barrier and its influence on heat and moisture movement through wall assemblies. It will review different compliance paths within recent versions of the IECC and ASHRAE 90.1, highlight key differences in the IgCC, and discuss how each approach can be effectively integrated into the design and construction process with the project team.