
Effective June 1, 2009
Subpart 1. Building envelope sealing. ASHRAE Standard 90.1, Section 5.4.3.1, is amended and subsections added to read:
5.4.3.1 Building envelope air sealing. The building envelope shall contain an air barrier consisting of a material or combination of materials to resist the passage of air into or out of the conditioned or semiconditioned space. The following areas of the building envelope shall be sealed in a permanent manner to minimize air leakage at all edges, joints, openings, and penetrations:
5.4.3.1.1 The air barrier shall be located between the warm-in-winter surface and the winter design dew point location within the building component or assembly.
Exception: When the building component or assembly is either integrally insulated concrete or integrally insulated concrete masonry.
Air Barrier Association of America
1600 Boston-Providence Highway
Walpole, MA 02081
866-956-5888