Vegetation in Zone 0: Amplifying Damage to Structures
Vegetation within the first five feet of a home—known as Zone 0—significantly increases heat exposure during a wildfire and can amplify damage, even when plants are well-watered.
Explore the full report to learn what our 17 controlled experiments revealed and how they inform future wildfire resilience strategies.
Research
Vegetation in Zone 0—the first five feet around a home—increases the intensity of the heat exposure the building experiences and can amplify the damage to homes during a wildfire. While established research defines the importance of the 5-foot noncombustible zone, IBHS conducted a series of tests specifically focused on the impact of vegetation within this area.
Key Takeaways:
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- Damage Amplifiers: Vegetation in Zone 0 amplifies the damage to homes, increasing the likelihood of structure ignitions and the severity of damage.
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- Moisture: Even well-hydrated plants will ignite and burn in conditions common during a suburban wildfire conflagration. The moisture content of plants increases the time to ignition, which in turn allows the structure to preheat longer, making the structure more susceptible to ignition when the vegetation in Zone 0 ignites.
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- Wind & Interventions: Local wind environments influence wind speed and direction. These fluctuations, along with firefighter interventions, help explain some of the contrasting observations regarding consumed and unconsumed vegetation documented in the field during post-event damage investigations after a conflagration.
What This Means
Zone 0 vegetation—regardless of species or moisture—poses a significant ignition risk to homes during wildfires.
Citation
Insurance Institute for Business & Home Safety. “Vegetation in Zone 0.” Insurance Institute for Business & Home Safety, 2025. https://doi.org/10.82346/KQX1-S839.
