WUI structure/parcel/community fire hazard mitigation methodology

This report documents the methodology and addresses the critical issues of mitigation effectiveness at the parcel and community level. It gives an implementable path forward by considering the spatial relationships between fuels, exposures, and hardening. In the last twenty years, wildland-urban interface (WUI) fires have grown in severity and size. The structures destroyed by WUI fires have devastated entire communities and have cost billions of dollars while significantly impacting the social fabric and economic well-being of entire regions.

To address this issue, the National Institute of Standards and Technology (NIST), the California Department of Forestry and Fire Protection (CAL FIRE), and the Insurance Institute for Business & Home Safety (IBHS) embarked on a sixteen-month collaborative effort, culminating in this Hazard Mitigation Methodology (HMM). The HMM demonstrates how complex structure hardening is, and how and why hazards associated with both fire and ember exposures need to be mitigated.