California Law Makes it Easier to Build Small, In-Home ADUs

New Law Signed by Gov. Gavin Newsom Removes Barriers, Imposes Standards

“It’s now easier than ever to build a home inside your home”

SACRAMENTO – Californians will find it faster, cheaper, and easier to add small accessory dwelling units (“ADUs”) inside their homes, thanks to new state legislation signed into law today by Governor Newsom. 

AB 1154, authored by Assemblyman Juan Carrillo (D-Palmdale) and sponsored by California YIMBY, UnidosUS, and Lieutenant Governor Eleni Kounalakis, clarifies rules for “Junior Accessory Dwelling Units” – or ADUs that are built within the envelope of existing homes, such as in garages or in parts of a home that are under-used or needed for additional residential space.

“A growing number of Californians realize that they can directly contribute to the housing needs of their families, or of their communities, by converting parts of their homes into ADUs,” said California YIMBY CEO Brian Hanlon. “We’ve seen tremendous built-up demand for these types of homes, and are thankful to Asm. Carrillo and Lt. Gov. Kounalakis for leading the charge on junior ADUs.”

California’s push to increase ADU construction has produced over 65,000 new, affordable homes statewide, but overlapping definitions and inconsistent standards have created unnecessary barriers for small accessory units. AB 1154 establishes a single set of clear rules for all ADUs under 500 square feet built within existing single-family homes.

The bill removes owner-occupancy requirements for JADUs with independent bathrooms, aligning them with ADU rules that have been in place since 2020. It also allows local jurisdictions to prohibit short-term rentals for JADUs, matching current ADU regulations.