California Laws & Regulations

City and county ADU ordinances

Cities and counties are not required to create their own city/county specific ordinances for ADUs; however, any city/county that does adopt an ADU ordinance, must submit the ordinance to HCD within or adhere to the recently passed California State ordinance on ADU/Granny Flats.  If your city has not submitted the information and is not listed on our list of City/County ADU Requirements below, you can try contacting your local building department.

New laws effective January 1, 2018

Recent state legislation provides clarification and fee assistance for the creation of ADUs. Governor Brown signed two separate bills on October 8, 2017: SB 229  (Wieckowski) and AB 494  (Bloom).

These bills, effective January 1, 2018, clarify and improve various provisions of the law to promote the development of ADUs, including allowing ADUs to be built concurrently with a single-family home, opening areas where ADUs can be built to include all zoning districts that allow single-family uses, modifying fees from utilities, such as special districts and water corporations, and reducing parking requirements.

Recent updates to state laws for ADUs / Granny Flats

State legislation that took effect January 1, 2017 gave California cities more flexibility and latitude for allowing homeowners to build ADUs. Three separate bills were introduced and signed by Governor Brown; SB 1069  (Wieckowski), AB 2299  (Bloom), and AB 2406  (Thurmond). Each of these land use bills make it easier than ever for homeowners to take advantage of this attractive opportunity.

Technical Assistance Booklet

Download entire booklet(PDF)

Information for cities, counties, other local government bodies, and homeowners interested in adding an accessory dwelling unit to their property.

Download the entire booklet (PDF) or select one of the following excerpts:

California Department of Housing and Community Development Webinar

12/20/2016 regarding the changes in the regulation of ADUs, frequently asked questions and answers!  This is a long one, over an hour and a half minutes long.  This was published as an accessory to the Technical Assistance Booklet on ADUs / Granny Flats.

Sample materials from cities and counties

Additional guidance

External websites

You’ll find additional resources at the following websites, which are hosted by partners who contributed to HCD’s Technical Assistance Booklet.