Study cites sustainable building materials as best wildfire defense
A new peer-reviewed study by Cal Poly faculty and scientists found that building density, not urban trees, was the strongest predictor of whether homes were destroyed during the Southern California wildfires in January 2025. The study’s key findings revealed that fire-resistant building materials, ember-resistant vents and roofs, as well as increased spacing between buildings, were the best solutions for wildfire prevention in the Los Angeles area.
The team examined 15,082 structures and 52,893 tree canopies within the Eaton and Palisades fire scars and evaluated the relative associations of urban canopy and structure density with structure damage. The study’s conclusion was clear: Houses packed closely together were far more likely to burn than homes in less dense neighborhoods, meaning the best practice for fire resilience and prevention is to build sustainably from the start.
“Our study shows that during extreme urban firestorms, houses become the primary fuel source,” said Reed Kenny, a Cal Poly biological sciences lecturer and the study’s lead author. “Once fire enters a neighborhood, structure-to-structure spread matters far more than the presence of trees.”
