Significance

Highly destructive wildfires are occurring more frequently across the globe, prompting debates over the causes for this increase and effective management responses. We investigated building destruction trends in the United States by mapping buildings that were exposed to and destroyed by wildfires over two decades. The proportion of exposed buildings that were destroyed more than tripled from 2002–2022, indicating that wildfires became more destructive in addition to burning more populated areas. This increase in destruction rate was linked to greater building exposure in forests, but destruction rates also increased in grass and shrublands and were influenced by weather, development type, and burn severity. Our findings suggest that diverse management approaches may be needed to reduce community vulnerability to wildfire disasters.

Abstract

Many regions of the world have seen an increase in highly destructive wildfires, driven by well-documented increases in burned area and growth of housing in the wildland–urban interface (WUI), which exposes more homes to fire. However, it is unclear whether wildfires are also becoming more destructive due to changes in wildfire behavior or in the development patterns of exposed communities. Here, we assessed trends in wildfire building exposure and destruction rates in the conterminous United States from 2002 to 2022. We mapped destroyed and surviving buildings within 100 m of all wildfires that destroyed 10 or more buildings (n = 362) and assessed trends relative to major ecoregions and vegetation types. We used logistic regression to assess relationships between destruction rates and landscape factors. We found that 10% of exposed buildings were destroyed in 2002–2012, but this percentage increased to 32% in 2013–2022. This increase was largely due to greater building exposure in evergreen forests in the northwestern United States, where exposed buildings were more than 3.4 times as likely to be destroyed as those in grass and shrublands. However, annual destruction rates also significantly increased in all other vegetation types and were correlated with development type, weather, and burn severity. These results indicate that increasing wildfire destruction in the United States has resulted not only from increased exposure but from rising rates of building destruction, potentially indicating more extreme wildfire behavior. This finding underscores the need to better understand how fuel management, community planning, and hardening buildings can reduce vulnerability.