Chapter 7 Interpretation: 2020 NGBS Section 701.4.3.4 Fenestration Air Leakage

Published Monday, December 30, 2024

NGBS 701.4.3.4 is a mandatory practice that specifies maximum air leakage rates for windows, skylights, sliding glass doors, and swinging doors. The NGBS requires fenestration products to be tested in accordance with NFRC 400 or AAMA/WDMA/CSA 101/I.S.2/A440 by an accredited, independent laboratory, as well as listed and labeled. This practice applies to fenestration in any building seeking NGBS Green certification: single-family; townhomes; multifamily; and mixed-use buildings.

Two compliance issues have arisen. First, Verifiers claim it is difficult to determine compliance for residential doors because they are not as commonly labeled as windows. Second, the windows and doors typically used for multifamily and mixed-use buildings follow a different reference standard for performance. 

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