ADU Construction Flourishing in Los Angeles County

Los Angeles County has permitted more accessory dwelling units per capita than any other California county, according to an analysis from the Los Angeles Times reported on by Terry Castleman.

Surprisingly, low- and middle-income cities are leading the charge as homeowners take advantage of new regulations to build additional units for family members and renters. The city of San Fernando permitted almost 70 ADUs per 1,000 existing housing units in the last six years, a number three times as high as the county average. The change in regulations also revealed the large number of unpermitted ADUs that already existed, many of which now have permits.

It is not fully clear why some cities are building more. Experts say the speed and ease of the permitting process in each city is a likely reason some cities are at the top of the list, but other factors could include differing municipal regulations and varying single-family lot sizes that dictate whether there is enough room for extra backyard structures.

According to industry experts, ADU owners in lower-income neighborhoods are more likely to rent out their units. “Cities that permitted more ADUs saw other benefits, the analysis showed: The 20 cities that added the most ADUs saw their housing stocks increase by 1.8% on average from 2018 to 2023, while the bottom 20 cities added only 0.5% in the same span.”