Lessons from the 2025 LA area fires

May 6

At the start of 2025, Los Angelos experienced a devastating wildfire that destroyed more than 16,000 structures and resulted in at least 29 deaths. It was ranked two of California’s three most destructive fires on record.

In the aftermath, there was been a surge of experts analyzing what happened to see what the lessons learned are and how we can create a future with a less destructive path forward.

The Insurance Institute for Business and Home Safety (IBHS) conducted a post-disaster investigation with a team of nine staff who evaluated 247 structures affected by the fire. They aimed to get a better understanding of:

the exposure to fire from both the wildland and the built environment,
the potential pathways for fire spread into communities, and
building materials and mitigation strategies that increase the likelihood of structural survivability.

Key Data Collected:

Building Type: 97% of the evaluated structures were single-family residential homes.
Roofing Material: The most common roof materials of the evaluated structures were asphalt shingles and clay or concrete tiles. 46% of the evaluated structures had an asphalt shingle roof. 18.6% had clay or concrete barrel tile, 11.8% clay or concrete flat tile.
Vents: Among structures with vents, only 7.8% had a 1/8-inch or finer metal mesh.
Wall Material: 80% of structures had stucco as the primary exterior wall material.
Windows: Window frames were most commonly metal (38%) and vinyl (34%).
Decks: 63% of the structures had decks, most commonly with a wood walking surface.
Fencing: Over 95% of the surveyed parcels had a fence, and in 61% of cases, the fence was either directly attached to the structure or located within Zone 0 (the 0–5 foot noncombustible zone). Additionally, 65% of fences were made of wood, increasing fire risk and serving as a dominant connective fuel.

Once the first few homes ignite in densely built neighborhoods, downwind structures are more likely to experience extreme heating by direct flame contact. Research from IBHS shows that with about 10 feet of separation between a fully engulfed structure and a downwind structure no building material on the downwind structure is likely to survive (in a large and uncontrolled wildfire). However, when the separation distance increases to approximately 20 feet, the benefits of fire-resistant building components become evident.

While wind patterns are beyond human control, reducing fuel connectivity and availability—by removing or spacing out combustible materials—creates an opportunity for fire-resistant building materials to mitigate damage.

To read the full report, download the report: IBHS 2025 LA Wildfires: Early Insights from Field Observations

The following video is a recording from a United Policyholders meeting that occured on April 9th, 2025. It features a panel of experts all of whom toured the impacted areas following the Los Angeles wildfires.