(Photo by Capri23auto via Pixabay)

The Contra Costa County Board of Supervisors have unanimously approved updates to the county’s accessory dwelling unit ordinance to comply with recent changes in state law designed to increase California’s affordable housing supply.

The new state laws give cities, towns and counties less input in what they can require of applicants wanting to build accessory units, also commonly called “granny flats” or “mother-in-law units.”

Local governments around the Bay Area have for months been updating such ordinances to conform to the new state laws.

County Supervisor Candace Andersen said making it easier to make such conversions is “a great way to develop more affordable housing.”

In October, Gov. Gavin Newsom signed several bills intended to increase the state’s supply of affordable housing. Accessory dwelling units are one part of the state’s ideal formula for providing more such housing.

The new laws took effect Jan. 1, and cities and counties all over California have been moving to adjust local ordinances.

The new laws mandate that cities and counties process applications for ADUs and junior ADUs “ministerially,” without discretionary staff review or public hearing for community comment.

The Contra Costa County supervisors’ action on Jan. 21 applies only to unincorporated areas, and not the cities within the county. Separately, applications for ADUs in the unincorporated community of Kensington would be subject to an additional design review for requirements specific to that community.