Currently, multiple areas of the United States are facing devastating losses and insurance crises due to increasing urban conflagrations, particularly in the wildland-urban interface (WUI). For many homeowners in the WUI, property insurance coverage has become unaffordable or unavailable. Effective wildfire mitigation requires careful prioritization to achieve the greatest risk reduction with limited resources, yet it is difficult to achieve a meaningful cost-benefit analysis using the current state-of-the-art wildfire catastrophe models. The WUI Data Commons (WDC) is a public and private initiative designed to systematically collect and store previously inaccessible wildfire mitigation and suppression data, while providing controlled access to a variety of users. This report, prepared for the California Fire Chiefs Association, contains the results of Milliman’s meetings and interviews with industry subject-matter experts. It also includes a detailed plan for Phase 3.

Key Phase 2 findings include the following:

• The rationale of the WDC centers on three key principles: increasing data availability, enhancing transparency, and fostering alignment.
• The WDC should help create alignment in the wildfire mitigation standards set by the state, the fire services, and the insurance industry, so that homeowners receive clear communication on wildfire mitigation priorities.
• The WDC should focus on data that is difficult to obtain, rather than compete with readily available data.
• The WDC should be able to process and compile both parcel-level and community-level data.
• There should be verified, inexpensive, easy-to-operate technology that can be used by homeowners and trusted third parties to inspect their homes and provide data to the WDC.