Alongside patios, pools and palm trees, Los Angeles backyards increasingly feature another element: small cottages for family members, renters or home offices.

The petite homes, meant to help ease the city’s housing crisis, are now becoming a key resource for residents displaced by the area’s devastating wildfires.

Residences known as accessory-dwelling units, or ADUs, have boomed in recent years, making up more than a third of the homes completed in Los Angeles County in 2023, according to state data. Many are now housing evacuees and are likely to be an important part of the building effort after the Palisades and Eaton fires, as California Governor Gavin Newsom seeks to fast-track construction in affected areas.