06 Jun 2023

Learn more about NAFS Requirements and its Canadian Supplement

In the building and construction industry, fenestration is a fancy name for windows, doors, and skylights. Windows, doors, and skylights add character and function to a building, but they also need to protect against the elements. During the manufacturing process, these products undergo performance testing to evaluate their ability endure various environmental factors such as wind, water, and air infiltration, as well as to assess their energy efficiency and acoustic performance. Fenestration testing helps to determine if components comply with and perform to building code and standards requirements, as well as to identify any areas for improvement. This enables architects, engineers, and building owners to select the most appropriate fenestration components for their projects, and to ensure that these components perform as expected for years to come.

Fenestration Testing in Canada

In this blog, we’re going to look at fenestration testing for products used in Canada, which is driven by the North American Fenestration Standard (NAFS). The 2022 edition of AAMA/WDMA/CSA 101/I.S.2/A440, North American Fenestration Standard/Specification for windows, doors, and skylights was published earlier this year and replaces the 2017 edition. As mentioned above, the products that fall under the NAFS include windows, doors, and skylights, with reporting requirements for physical testing.

CSA A440S1-19 is the Canadian Supplement to NAFS and includes calculations for the driving rain wind pressure (DRWP), wind loads, and snow loads amongst other calculations.

NAFS is a harmonized standard, meaning that a group of standard writing organizations collaborated to create a single standard that is accepted on both sides of the border.

Thermal simulations using air leakage values obtained from NAFS are conducted according to CSA A440.2.

Performance Classes

The different performance classes as per NAFS are:

  • R: commonly used in one- and two-family dwellings. (Part 9 Buildings) – Minimum requirement.
  • LC: commonly used in low-rise and mid-rise multi-family dwellings and other buildings where larger sizes and higher loading requirements are expected. (Part 9 Buildings)
  • CW: commonly used in low-rise and mid-rise buildings where larger sizes, higher loading requirements, limits on deflection, and heavy use are expected. (Part 5 or 9 Buildings)
  • 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 is expected. (Part 5 Buildings)

NAFS table 12.2 outlines the required testing based on these performance classes.

The Testing Process

When a customer comes to us to conduct fenestration testing, a key thing we look at is the client's target market and the targeted end use of the product. This changes how we approach the project as it will change the scope of testing since each performance class has its own set of tests and performance requirements.

We start by gathering information to determine the product or product line to be tested and certified as well as the necessary documentation. For certification of a new product or if the client is new to Intertek, we conduct a site audit to document and outline the manufacturing and quality control processes.

The next step is physical testing. Depending on the target market, fenestration products are tested to NAFS and the Canadian supplement. This data is then used to create a thermal performance model, which is then followed by a certification listing, and finally submission to ENERGY STAR.

Intertek is an approved Certification Body per NRCan and can submit to the ENERGY STAR program on behalf of fenestration products manufacturers. Through the Intertek Certification process, clients are able to label their products with the Intertek Certification mark as well as work with NRCan to obtain ENERGY STAR labels.

If you would like more details about the certification process for fenestration products within Canada, watch our on-demand webinar, Fenestration – Canada: NAFS Testing, Certification, and Path to ENERGY STAR.


Kareem Abdelghany Intertek headshot

Kareem Abdelghany,
Technical Analyst

Kareem Abdelghany is a Technical Analyst within the Canadian Evaluation Services team with more than four years of experience in the building products industry. His expertise spans a wide range of product streams, including fenestration products, insulation systems, and fire doors. With his technical experience in code compliance, Kareem has supported numerous clients on both coasts of the country by managing certification projects that bring new products to the North American market.


Mohamad-Nawaf Taleb Intertek headshot

Mohamad-Nawaf Taleb,
Account Manager

Moe has been with the Intertek team since 2019 and comes to us with more than five years of experience from the testing and certification industry. Moe leverages his more than eight years of experience to build relationships and successful partnerships with his clients that have benefited from his academic and professional expertise. From one-time initiatives to complex and ongoing compliance strategies, he continues to support the building and construction industry's ever-changing needs.

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