Wildfires, Windows, and the Building Code

The changing climate is causing a number of issues for Canada, as evidenced by 2023 being the worst wildfire season ever recorded. These fires, and the smoke they create, pose risks to both property and health. So, have building codes changed to take these dangers into account? Are new regulations in place to help protect people? We investigated for the latest edition of the Window Geeks: Master Class.

What do the Building Codes say About Wildfires?

Despite national and provincial building codes undergoing recent updates, neither wildfires nor forest fires are specifically mentioned anywhere, in window and door-specific sections or otherwise. This applies to the latest versions of the National Building Code, the BC Building Code, and the Alberta Building Code as of 2024.

That’s not to say builders and developers don’t need to take wildfires into account. For mention of how development should be undertaken when there’s a wildfire risk, we can look to other, often more local regulations, such as the Okanagan’s Rural Westside Official Community plan:

“The Wildfire Interface Construction Development Permit Area designated pursuant to section 919.1 (1) of the Local Government Act for purpose of protection of development from hazardous conditions. All habitable land uses require a Development Permit.”

Always be sure to look into local regulations whenever you’re undertaking a development in a new area. The Window Geeks have also encountered wildfire-specific bylaws on projects in places such as Squamish (BYLAW NO. 2809, 2021).

Wildfire protection through Building Code.

Despite not mentioning wildfires or forest fires specifically, there are plenty of regulations in our Building Codes that cover fire safety and can relate to protection from wildfires. One such rule is seen in the BC Building Code: all windows must be double-paned or tempered.

Glass can be shattered by the heat of a fire and create openings for fire and burning debris to enter the building. It is highly unlikely that an interior will ignite from thermal radiation through intact glass. A single pane thickness of glass is most susceptible to collapse. The larger the pane of glass, the more likely it is to shatter.

– Wildfire Interface Construction Development Permit Objectives and Design Guidelines, July 15, 2021

Improved wildfire safety for windows and doors.

Single-pane windows would not conform with wildfire guidelines, but a reputable manufacturer would no longer sell them anyway. There’s little reason to enforce wildfire protection when it comes to windows and doors beyond what is already required by regulations – an important consideration is that a window or building material (such as those that make up a wall) should provide adequate barriers from the exterior. This is mentioned in section 5.3 of the National, BC, and Alberta versions of the Building Codes, covering heat transfer:

5.3.1.1 Required Resistance to Heat Transfer

1) Except as provided in Sentence (2), where a building component or assembly will be subjected to an intended temperature differential, the component or assembly shall include materials to resist heat transfer or a means to dissipate transferred heat in accordance with the remainder of this Subsection.

Windows must be at least double pane in order to be code compliant, and therefore would automatically meet wildfire regulations. All windows shall meet the heat transfer performance requirements stated in Section 5.3.

If you have an upcoming project you need help with, be sure to speak to the Window Geeks.