Findings combined with laboratory testing show home hardening and noncombustible Zone Zero are critical to reducing damage in suburban conflagrations
RICHBURG, S.C., Dec. 10, 2025 /PRNewswire/ — The Insurance Institute for Business & Home Safety (IBHS) released findings today from its post-event investigation of the 2025 Los Angeles County Fires, illustrating the necessity of a systems-based approach to wildfire resilience. Using new quantified data, the report, The 2025 LA Conflagrations, shows homes were more likely to avoid damage in conflagration conditions when there was greater spacing and lower connective fuel density, including vegetation, allowing noncombustible building materials to perform as intended.
The findings are based on IBHS’s on-the-ground assessment of the Eaton and Palisades Fires —California’s second and third most destructive wildfires — conducted January 13-19, 2025, during which researchers assessed more than 250 properties. Findings from the study are consistent with other suburban conflagrations, including the Camp and Lahaina Fires, and quantify for the first time the major role a complete system of mitigations plays in preventing zip code-level destruction.
“This study underscores a critical truth: in densely built communities like Los Angeles where we can’t change structure spacing, only a system of mitigations can keep wildfires from cascading into block-by-block destruction,” said Roy Wright, president and CEO of IBHS. “Home hardening and a noncombustible Zone Zero are essential to remove the weak links fire looks to exploit. When homeowners take these actions, we dramatically increase the chances that people can return to their homes after a fire. That’s hope grounded in science.”
Drawing on detailed data collected from a subset of impacted structures and coupled with a broader damage inspection dataset from CAL FIRE, the report provides a comprehensive picture of how structure spacing, connective fuels and building materials work together to determine outcomes when wildfire enters suburban neighborhoods. Analyzing homes affected across both fire perimeters found that homes with four key hardening features — including a Class A roof, noncombustible siding, double-pane windows and enclosed eaves — had a 54% likelihood of avoiding damage, compared to just 36% when only a single action was taken. Additional analysis from the IBHS damage investigation showed that more than 25% fuel coverage in Zone Zero pushed the risk of damage or destruction to nearly 90%. Because spacing cannot be changed in most existing communities, these findings highlight the powerful steps homeowners can take today to strengthen their homes and help slow structure-to-structure spread, reducing the likelihood of the widespread damage seen in the LA County Fires.
A second report, Vegetation in Zone 0: Amplifying Damage to Structures, reinforces the importance of a noncombustible Zone Zero through 17 experiments conducted at the IBHS Research Center. The results show that vegetation within the first five feet of a home significantly increases heat exposure during a wildfire and can amplify damage, even when plants are well-watered. Healthy vegetation adjacent to homes can dry out in minutes during a conflagration event creating ignition pathways consistent with the patterns seen in Los Angeles County and other suburban fires. These findings align with what IBHS documented in Los Angeles, where vegetation and everyday items like hot tubs, patio furniture and trash bins in Zone Zero repeatedly served as connective fuels that carried fire to vulnerable building features.
“When we walk through these neighborhoods after a wildfire, the story of how the damage unfolded becomes unmistakable,” said Murray Morrison, PhD, managing director of research at IBHS. “Wildfire doesn’t sweep through in a perfect line; it finds weak spots, one by one. These damage patterns allow us to see where homeowners have real opportunities to interrupt that chain of conflagration, protect their homes and protect their neighbors.”
Insights from the IBHS survey of 252 structures were further strengthened by CAL FIRE’s Damage Inspection Program (DINS) data, which documented broad damage across more than 30,000 structures in both fires. While DINS data captures the overall patterns of loss, the IBHS field data helps explain why individual homes ignited, revealing the role of nearby fuels and building vulnerabilities. See the full reports at ibhs.org/lawildfires/.
About the Insurance Institute for Business & Home Safety (IBHS)
The IBHS mission is to conduct objective, scientific research to identify and promote effective actions that strengthen homes, businesses and communities against natural disasters and other causes of loss. Learn more about IBHS at ibhs.org.
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SOURCE Insurance Institute for Business & Home Safety
