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Consult the New Version of NAFS for Industry Answers

NAFS is regularly updated to address market trends, technology, building codes and rating systems

Whether building a new home or upgrading an old one, homeowners and residents want to know the window, door and skylight products they choose will comply with code, perform well, operate easily and deliver realistic benefits.

When homeowners have questions about fenestration performance, they turn to builders, contractors and manufacturers. When manufacturers, contractors, architects and others in the industry have questions, they consult the NAFS for answers.

Complies with codes

The AAMA/WDMA/CSA 101/I.S.2/A440, North American Fenestration Standard/Specification for windows, doors, and skylights (NAFS) offers a performance-based, material-neutral means to evaluate products. First jointly published in 2005, with individual roots tracing to the early 1960s, NAFS is regularly updated to address changes in market trends, technology, building codes and rating system performance requirements.

The 2017 edition of NAFS, NAFS-17, is currently referenced in the 2021 editions of the International Building Code and International Residential Code in the U.S. Released in February 2023, NAFS-22 is proposed for inclusion in the 2024 editions of these codes. NAFS-17 is also referenced in the 2020 edition of the National Building Code of Canada, with NAFS-22 proposed for inclusion in the 2025 edition.

Anticipating future code adoption, manufacturers can start testing now to ensure their products meet the new standard. NAFS-22 has been simplified, streamlined and reorganized so users can easily find the information they need.

Performs well, operates easily

One of the goals of NAFS-22 was to continue the U.S. and Canadian harmonization, maintaining stringent requirements acceptable to both countries. This has led to a cross-border expansion of performance requirements. For example, in the U.S., air-leakage requirements now include exfiltration (interior air leaking outside) and infiltration (exterior air leaking inside).

NAFS-22 also achieved a balance between U.S. and Canada for operating force requirements. NAFS-22 combined operating force tables to include all product types and performance classes. A single requirement now identifies the maximum force to initiate and maintain movement.

Homeowners continue to prioritize natural ventilation and indoor-outdoor connections, and ever-larger openings. The demand for expansive multi-panel folding doors has grown since these products were first included in NAFS-17. Responding to this market trend, NAFS-22 has expanded the definition and configurations for folding doors.

Delivers realistic benefits

NAFS performance class designations assist in matching fenestration performance to project requirements and consolidating testing requirements for manufacturers. The R, LC, CW and AW performance class designations for windows and doors have been in place since NAFS-08. (See the box on p. 22 for explanations of each designation.) The typical applications for each of these performance classes are defined within NAFS-22.

In NAFS-22, performance class R products no longer require a minimum test size. Now, manufacturers test these products using sizes they commonly manufacture, rather than a required sample size.
When homeowners are confident in the performance of their windows, doors and skylights, our whole industry benefits. 

Performance Class Designations

  • R: commonly used in one- and two-family dwellings.
  • LC: commonly used in low-rise and mid-rise multi-family dwellings and other buildings where larger sizes and higher loading requirements are expected.
  • CW: commonly used in low-rise and mid-rise buildings where larger sizes, higher loading requirements, limits on deflection and heavy use are expected.
  • AW: commonly used in high-rise and mid-rise buildings to meet increased loading requirements and limits on deflection, and in buildings where frequent and extreme use of the fenestration products are expected.



Janice Yglesias FGIA

Janice Yglesias

Janice Yglesias is the executive director of FGIA overseeing the full organization. She joined the association in 1999 and can be reached at