The 2026 edition of AAMA/WDMA/CSA 101/I.S.2/A440, commonly known as the North American Fenestration Standard (NAFS), has officially been released, marking the latest update to the industry’s most widely recognized performance standard for windows, doors and skylights.

Developed through a joint effort between the Fenestration and Glazing Industry Alliance (FGIA), CSA Group and the Window & Door Manufacturers Association (WDMA), NAFS undergoes a mandatory review every five years to ensure alignment with evolving industry requirements, testing methodologies and building code expectations across North America.

While NAFS-26 does not introduce sweeping technical revisions, one significant change addresses the use of the secondary performance designator. Previously optional, the secondary designator is now mandatory and must appear on product labels and test reports. The designation provides additional transparency by identifying three critical performance metrics: positive design pressure, negative design pressure and water penetration resistance test pressure.

The revision originated from a proposal submitted by the Federal Emergency Management Agency (FEMA), driven by growing concerns regarding water intrusion performance in coastal and hurricane-prone regions. Following discussions between FEMA representatives and the Joint Document Management Group (JDMG), the proposal was accepted and incorporated into the new standard. The update also reflects recommendations previously raised by the Florida Building Commission, where resistance to extreme weather conditions remains a key regulatory focus.

NAFS continues to serve as the primary performance benchmark referenced throughout North America. The standard is incorporated into major building regulations, including the International Building Code (IBC), International Residential Code (IRC), International Energy Conservation Code (IECC) and Canada’s National Building Code (NBC). The 2022 edition is already referenced within the latest code cycles, while NAFS-26 is expected to be integrated into future editions, including the 2027 IBC and IRC updates.