The Insurance Institute for Business & Home Safety inspected more than 250 homes in Altadena and Pacific Palisades and found that removing vegetation and combustible materials within the first five feet of a house strongly correlated with lower destruction rates (27% destroyed where most of the zone was vegetated vs. 9% where under 25% was). Hardened homes with noncombustible roofs and other fire-resistant features survived far better when spaced at least 20 feet apart. Experts say the findings are exploratory but align with lab research and broader studies; California is weighing draft "zone zero" rules that would restrict fences and possibly vegetation near homes while studying affordability and implementation.
Clearing the First Five Feet: Early 'Zone Zero' Steps Linked to Higher Home Survival in L.A. Fires
Dec 11
Damage to homes burned in the Palisades fire can be seen above Pacific Coast Highway in Malibu on Jan. 25.(Brian van der Brug / Los Angeles Times)
As the Eaton and Palisades wildfires raced through neighborhoods of tightly spaced houses, homeowners who took early, low-cost steps—like removing vegetation and combustible items within the first five feet of exterior walls and upgrading vulnerable materials—were notably more likely to save their homes, an insurance-backed field investigation found.
Field Inspection Found Large Differences In Damage Rates
Over a week in January while fires were still active, the Insurance Institute for Business & Home Safety (IBHS), a nonprofit funded by the insurance industry, inspected more than 250 properties in Altadena and Pacific Palisades, including destroyed, damaged and unscathed homes. Where most of the immediate five-foot zone remained covered in vegetation and other flammable materials, 27% of homes were destroyed. Where under a quarter of that zone contained such materials, only 9% were destroyed.
Home Hardening And Spacing Also Matter
The IBHS team also evaluated "home hardening" features—noncombustible roofs, fire-resistant siding, double-pane windows and closed eaves—and cross-checked state fire data. Hardened homes at least 20 feet from neighboring structures survived without damage at least 66% of the time. When spacing dropped below 10 feet, the undamaged rate fell to 45%.
"The spacing between structures, it’s the most definitive way to differentiate what survives and what doesn’t," said Roy Wright, president and CEO of IBHS. "At the same time, it’s not feasible to change that."
How Vegetation And Small Fuels Help Fires Spread
Inspectors documented multiple ignition pathways tied to vegetation and other items in the immediate perimeter of homes. Embers ignited hedges near a house, and heating shattered a single-pane window, allowing embers inside. Embers also landed on trash and recycling bins, burning through plastic lids and igniting contents that then spread to garages or siding. Wooden decks and fences frequently acted as bridges for flame to reach structures.
Context, Caveats And Broader Evidence
IBHS noted its findings are exploratory and consistent with laboratory tests that trace how embers and flames enter homes. Independent experts urged caution about drawing causal conclusions. Travis Longcore of UCLA said the team did not analyze some potentially important variables—such as home age—and that IBHS’s definition of "zone zero" does not exactly match California’s draft rules. UC Berkeley fire researcher Michael Gollner said the sample focused on properties that were accessible during active firefighting and may not fully represent entire burn areas.
Still, other research supports the pattern. A separate study led by Gollner that examined more than 47,000 structures across five major California fires found 37% survival for properties that removed vegetation from the immediate zone, compared with 20% survival for those that did not.
Policy Debate: Draft "Zone Zero" Rules And Concerns
California’s draft "zone zero" regulations would address some risks: proposed rules ban wooden fences within five feet of a home and are considering whether to prohibit or limit nearly all vegetation in that zone (well-maintained trees would still be allowed). The draft does not currently ban trash bins in the five-foot zone or require homeowners to replace wooden decks, citing enforcement and cost challenges.
"A focus on vegetation is misguided," said David Lefkowith, president of the Mandeville Canyon Association, reflecting concerns about costs and homeowner burden.
The Board of Forestry and Fire Protection has asked staff to further study affordability and implementation. Tony Andersen, the board’s executive officer, said officials must balance "safety, urgency, and public feasibility" while identifying resources to help homeowners comply.
Practical Takeaways
IBHS recommends a layered approach: combine defensible-space actions (clearing immediate vegetation and fuels) with home-hardening measures (noncombustible roofing, ember-resistant vents, double-pane windows and fire-resistant siding). Inspectors also acknowledged that firefighters likely saved many near-miss homes, and experts emphasize complementary strategies — ignition prevention, community coordination, and wildland management — to reduce overall risk.
Note: This article synthesizes reporting adapted from the Los Angeles Times and the IBHS field investigation.
