The paper will explore the air barrier requirements in Model building codes and standards referenced in the US and Canada, address misconceptions, and will work to outline a framework for a path forward to improve these documents. Beginning with a brief history of air barriers in model codes and standards, we will review the requirements of the 2018 IECC and the 90.1‐2016 as well as changes from their
earlier versions.

The focus will be on the language, use, and impacts of sections covering:

• Air barrier definition
• Air barrier design and installation
• Air barrier testing
• Air barrier modeling
• Air barrier impact by climate zone

This foundation of understanding will move is to exploring a series of questions:

• What are the next steps in these activities of defining the minimum air barrier ‐ 0.40/0.30/0.25/0.15/0.10? Case studies?
• Is mandatory whole building air testing on the horizon?
• Should requirements for air barriers per climate zone vary?
• What is the supporting analysis needed to move the codes and standards to the next level?
• Is the a point of diminishing return based on the analysis construct in code?

The current data shows buildings designed today with an air barrier and following the intent of the codes and standards should have the components and design to achieve 0.30 when installed with the standard of care. What is the cost of asking people to take care in their work in design and construction? Are we appropriately capturing the impact of air leakage of our buildings in the modeling analysis to support the economic justifications? Does the air leakage calculation impede our ability to make an economic justification?

• Infiltration schedules?
• Latent energy from infiltration?
• Fan power required for exfiltration?
• First cost changes based on downsizing equipment, ductwork, etc?