Friday, October 2nd, 2026 — Wildfire exposure can vary substantially from one property to another even within California communities broadly classified as high risk, according to a case study from the Insurance Information Institute and Guidewire HazardHub. The analysis examined whether parcel-level modeling could identify meaningful differences that broader ZIP-code assessments may overlook.
The model considers factors including vegetation and fuel load, slope, historical fire activity, ignition potential, defensible space and access to firefighting resources. In some ZIP codes with an average wildfire score of 0.60 on a 0-to-1 scale, individual properties scored as low as 0.25. Researchers also identified lower-scoring parcels in Napa, Shasta and Santa Cruz counties where terrain, irrigated land, firebreaks or property-level mitigation reduced modeled exposure.
The findings come as California insurers and regulators continue to address coverage availability in wildfire-prone areas. Some carriers have reduced exposure or limited new business in portions of the state, while broader geographic risk classifications can group properties with significantly different hazard characteristics. More detailed models could allow insurers to distinguish among those properties rather than treating an entire ZIP code as having comparable exposure.
Mitigation was another significant factor in the analysis. Properties with defensible space, vegetation management, hardened building materials and ember-resistant features showed substantially lower modeled risk, with the study citing reductions in damage risk of as much as 70%. Community measures such as vegetation management, infrastructure planning and coordinated fire response can also influence exposure.
For claims professionals, greater property-level detail may provide useful context before and after wildfire losses. Information about construction features, defensible space, surrounding vegetation and local fire behavior can help clarify why neighboring properties experience very different outcomes during the same event. Higher-resolution data may also improve catastrophe planning and help insurers understand concentrations of exposure within communities.
The study arrives as California implements its Sustainable Insurance Strategy, which includes efforts related to insurance availability, mitigation recognition and catastrophe modeling. The approach could also draw attention from other wildfire-prone states as insurers and regulators consider how more granular risk data might affect underwriting, pricing and mitigation programs.
