When I began working with my first set of construction drawings for a net-zero-energy home in 2020, the third page of my drawing set contained something I had never seen before in my design work: a drawing sheet specifically devoted to air-sealing details. The design and construction industry is slowly coming up to speed about the role the air barrier plays in comfort, durability, and energy efficiency. Still, designing and building a continuous air barrier is the exception and not the rule. Devoting a drawing sheet to thorough and clear air-sealing details is just one of the strategies we employ to set the builder up for success in high-performance building. In this article I’ll take you through the designer and draftsperson’s perspective on some of the critical details we include on this sheet. If you’re looking for higher-level information on the air barrier, check out these articles:

• Getting Started with Air Sealing by Brian Pontolilo
• Passing a Blower Door Test by Randy Williams
• Questions and Answers about Air Sealing by Martin Holladay

Design the air barrier and include it in your plans

If you’ve spent time researching air-barrier strategies, you’ve likely heard about the redline (or red pen) test. If you haven’t, it’s this: On each building section in a drawing set, use a red pencil or pen to trace the entire air-barrier assembly. If you have to “stop the line,” or pick up your pencil, the design may not have planned for full continuity of the air barrier. The air-sealing sheet we include on our drawings is essentially an extension of the redline test, allowing us—and the builder—to plan for the connection points in greater detail, all in one place. We include a short narrative section on our air-sealing details sheet that emphasizes the importance of a…