Building for Wildfire Resilience

Wildfires are becoming more frequent, more intense, and more destructive across North America. According to the Canadian Interagency Forest Fire Centre, the 2023 wildfire season burned nearly 18 million hectares of land, far exceeding the 10-year national average. In the U.S., states like California continue to experience record-breaking fire events that threaten entire communities.

As wildfires increase in severity, architects, engineers, and builders are under growing pressure to design structures with increased odds of surviving these new extremes. Jurisdictions like British Columbia and California have updated their building codes and guidelines to prioritize wildfire resilience, particularly in Wildland-Urban Interface (WUI) zones. These are the areas where development meets natural vegetation, and where building materials and design choices matter most.

In any building envelope, windows are often the most vulnerable component during a wildfire. Even if the walls are fire-resistant, a window failure can allow radiant heat, flame, or embers to enter the building and destroy it from the inside out.

There are two main points of failure. First, thermal breakage of the glass can occur when the outer pane quickly heats up unevenly, causing it to crack or shatter. Second, thermoplastic window frames like vinyl can melt, deform, or ignite under high heat, compromising the entire opening.

Think of it like sunscreen. A high-SPF product does not make you immune to sunburn, but it gives you more time and protection. Wildfire-resistant windows work in a similar way. They cannot stop every fire, but they offer much greater resilience under extreme conditions.

Despite the growing wildfire risk, many designers remain unaware of how much window frame materials vary in their ability to resist fire. With limited standards and little widespread industry guidance, that’s understandable. But it also means many buildings may be more vulnerable than they need to be. That’s where fiberglass comes in.

Want to dive deeper into the risks and design strategies for wildfire zones? Join our free webinar: Wildfire Resistance: Window Strategies for Wildland-Urban Interface (WUI) Design.

We’ll cover key fire exposure mechanisms, guidance from California and FireSmart BC, and how to specify high-performance window systems that meet the demands of wildfire-prone environments.

For architects and builders who need clear guidance on material performance, detailing, and code alignment, we’ve developed a 3 part specification package focused on wildfire-resilient window design. It outlines key requirements, recommended practices, and technical considerations to support informed decision-making in WUI and high-risk zones.

3 Part Specification - CSC    3 Part Specification - CSI