Why You Need the Newest Version of NAFS

A new version of the North American Fenestration Standard (NAFS) is now available! In June, the Joint Document Management Group (JDMG), comprised of representatives from the three associations, released the 2026 edition of AAMA/WDMA/CSA 101/I.S.2/A440, North American Fenestration Standard/Specification for windows, doors and skylights. This standard is reviewed and updated by members of the Fenestration and Glazing Industry Alliance (FGIA), Window & Door Manufacturers Association (WDMA) and CSA Group no less than every five years, to stay up to date with changes in the industry. FGIA thanks CSA and WDMA for their hard work on this update!

NAFS-26 replaces the 2022 edition, representing a continued evolution of the standard while improving harmonization across North America. But what has changed? This column provides an overview, as will a session that I am leading on the Main Stage at GlassBuild America on September 24th. If you’re going to GlassBuild, don’t miss my presentation, “NAFS-26 | Understanding Key Changes and Impacts on Testing Requirements,” taking place at 2:20 p.m.! (And be sure to visit the FGIA team in Association Row, Booth AR-04, throughout the event.)

Secondary Designators, Explained

The most significant change in NAFS-26 is the requirement for a secondary designator on fenestration product certification labels in the U.S. Consultants working with the Federal Emergency Management Agency (FEMA) provided the JDMG with code change proposals they had developed for consideration by several code entities including the International Residential Code (IRC), International Building Code (IBC) and Florida Building Code (FBC). If adopted, these proposals could have created an alternate pathway for fenestration product approval that potentially would not have provided the same level of completeness or consistency as the existing NAFS process.

Because the members of the JDMG are also involved in building codes development, there was an established line of communication that allowed the organizations to work collaboratively with FEMA representatives to determine how the concerns could best be addressed.

The JDMG felt NAFS could be updated to address the concerns while continuing to provide a comprehensive standard that meets the needs of the fenestration industry and establishes consistent requirements for both manufacturers and users. The JDMG met with FEMA representatives and reached an agreement on how their concerns could be addressed through targeted revisions to NAFS.

The primary concern involved the information provided on product certification labels used in the U.S. Historically, the performance grade (PG) shown on a label represents the PG (R, LC, CW, AW) for which all applicable performance criteria have been met, including the required ASD design pressure. However, previous labels were not required to include specific pressures and test levels that a product had been tested to and passed. That information was only included on the label if a secondary designator was included.

NAFS-22 (Clause 4.6.3.1), as well as previous editions of the standard, permitted an optional secondary designator on the certification label. This designator provides additional information including the tested positive and negative design pressures, water penetration resistance test pressure and air leakage test pressure. In NAFS-26, the inclusion of these additional test-pressure values is mandatory, except for the air leakage test pressure, which is optional. Making the secondary designator mandatory provides more transparency between the actual performance demonstrated by the product during testing and the required test levels of the PG. Examples and related references throughout the standard have been updated to reflect this requirement.

Certification label users can now easily obtain detailed information about the product's tested performance and its corresponding PG rating. This information is particularly valuable to local building officials, specifiers and architects when evaluating products for specific applications.

Following these discussions, and after incorporating revisions into the updated standard, the FEMA-related code change proposals were not submitted. NAFS-26 resolves the concerns within the established fenestration product approval framework, which helps maintain consistent requirements for manufacturers, code officials and other users of the standard.

NAFS and Code Adoption

Since NAFS includes all the requirements for fenestration products, it has been adopted in many different code bodies including the national building codes of both the U.S. and Canada through the IBC, IRC, International Energy Conservation Code (IECC) and National Building Code of Canada (NBC). As states, provinces and municipalities adopt the national codes, NAFS becomes part of these more localized codes.

The 2022 NAFS standard is referenced in the 2024 editions of the IBC and the IRC, with the recently released NAFS-26 proposed to be included in the 2027 editions of these codes. The 2022 NAFS standard is also referenced in the 2025 edition of the NBC, and NAFS-26 is proposed to be included in a future edition.

An equivalency document for NAFS-26 will be developed later this year, providing guidance for compliance regarding testing to one version of NAFS versus another.

How to Purchase Your Copy of NAFS

AAMA/WDMA/CSA 101/I.S.2/A440-26 is available online at Fenestration and Glazing Industry Alliance, Window & Door Manufacturers Association or CSA Group.