One-third of U.S. homes sit in the wildland-urban interface but most local jurisdictions have not adopted wildfire-resistant building codes because officials mistakenly believe compliant construction costs significantly more

Approximately one-third of all U.S. homes—tens of millions of structures—are located in the wildland-urban interface (WUI) where flammable vegetation meets residential development, but the vast majority of local jurisdictions outside California have not adopted the International Wildland-Urban Interface Code (IWUIC) or equivalent wildfire-resistant building standards, leaving new construction in high-risk areas built to the same combustible standards as homes in low-risk urban cores. The primary barrier is the widespread but empirically false belief among local officials and builders that wildfire-resistant construction is significantly more expensive. Why it matters: Every year thousands of new homes are built in WUI areas to conventional combustible standards (wood siding, unscreened vents, standard single-pane windows), so these homes ignite from ember exposure during wildfires that homes built to IWUIC standards would survive, so wildfire property losses continue to escalate decade over decade (insured wildfire losses exceeded $15 billion in multiple recent years), so insurance companies respond by non-renewing policies in entire zip codes rather than differentiating by construction type, so even homeowners who voluntarily harden their properties lose coverage because the community-level risk remains high. The structural root cause is that building code adoption in the U.S. is a local government decision (not federal), and county commissioners and city councils in WUI areas resist adopting wildfire codes because builders and developers lobby against them citing cost concerns, even though Headwaters Economics and the Insurance Institute for Business & Home Safety (IBHS) have found that a new home can be constructed to wildfire-resistant standards for approximately the same cost as a conventional home—the cost difference for WUI-compliant roofing, vents, fascia, soffits, and gutters is approximately $5,860 (27% of roof cost) on new construction, and some fire-resistant materials actually have longer lifespans and lower maintenance costs.