2021 ICC Building Code Updates Part 3 – AVBs

This SpecTopic is the final installment in our multi-part series focusing on upcoming changes to the 2021 International Code Council’s (ICC) International Building Code (IBC) and International Energy Conservation Code (IECC).

The final proposals of 2019 were heard in Las Vegas, Nevada, in October, and the ICC has released their online consensus vote results. While this is not an exhaustive list, several changes focusing on air and vapor barriers are listed below.

IECC Section 401.2 Application adds text and clarification for compliance with an energy model path of either IECC or ASHRAE 90.1. This clarification cleans up the language currently in the code.

IECC Section 402.5.1 Air Barrier Compliance adds new language and a requirement for testing of air barriers during construction for individual dwelling units in Group R and I occupancies. A building with fewer than eight units will need to test all units, while buildings with more than eight units will need to test 20% of the total number. There is an exception for buildings in Climate Zones 2B, 3B, 3C, and 5C, and some other exceptions based on project size.

IECC Section 402.5 Air Leakage adds test method ASTM E3158, a test method for measuring the air leakage rate of a large or multizone building.

IECC Section 402.5.1 Air Barriers adds a new section to require a building envelope performance verification for all projects, except those in Climate Zone 2B. This verification can be done by the code official, a registered design professional, or an approved agency.

IECC Section 402.5.1.2.2 Assemblies adds test method ASTM D8052 for low-slope roofs. ASTM D8052 is a test method for quantification of air leakage in low-slope membrane roof assemblies.

For more information on the code development process, visit the ICC website here.

Contact Craig Tyler at [email protected] with further questions.