Why Implement HMM in your Community?

WUI Structure / Parcel / Community Fire Hazard Mitigation Methodology (HMM)

HMM is an exposure-centered approach to structure/parcel and community hazard mitigation. The methodology was designed specifically to address hazard mitigation of existing communities but can also be considered when developing new communities.

HMM is fundamentally different from previously developed parcel-centric approaches.

HMM is an Exposure-Centric, Community Approach

HMM is designed to work across the entire community, not just individual properties. It is a community-wide mitigation methodology that, once implemented and maintained, will significantly reduce structural fire losses due to wildland and WUI fires.

The proposed method has two goals:

1. Protect homes and property to reduce loss,
2. Prioritize cost-effective protection.

This can be achieved by balancing mitigation efforts to reduce potential fire and ember exposures and hardening structures to resist ignition. This can be visualized using the two dials shown below representing these two components. There is a direct relationship between exposure and the structure hardening required for structure survival; effective mitigation is a tuned balance of these two components. There are as many relationships that will result in structure ignition as there are relationships or settings that will result in no ignition. At one extreme, if exposures (both fire and embers) are eliminated then no hardening is required. Conversely, if a structure is hardened to a windowless concrete bunker, for example, it could survive an extreme exposure.

WUI fire hazard mitigation is a balance between two input dials:
reducing exposure and increasing structure hardening.