Accessory Dwelling Units (ADUs) and Junior Accessory Dwelling Units (JADUs)

ADUs and JADUs

An Accessory Dwelling Units, or ADUs, are small to medium sized residential units (up to 850-1,000 sq. ft. depending on the size of the lot) that are located on the same lot as a single family or multiple family dwelling.  They contain a kitchen, sleeping facilities, and full bathroom facilities.

A Junior Accessory Dwelling Units, or JADUs, are small residential units (no more than 500 sq. ft.) built within a single-family dwelling or an existing accessory building.  They include an efficiency kitchen and sleeping facilities, and can include their own bathroom, or share a bathroom with the single family dwelling.  Properties with a JADU must be owner occupied.

ADUs and JADUs provide housing opportunities through the creation of small rental housing units that meet the housing needs of individuals and families, particularly those of low and moderate income.  They allow a more efficient use of the City's existing stock of dwellings, provide economic support for resident families of limited income, and provide rental housing units for persons who are elderly or disabled.

City Zoning Regulations

ADUs are allowed in all single family residential, multiple family residential, and mixed use zones.

JADUs are allowed in all single family residential zones, and multiple family residential zones that allow single family dwellings. 

ADU and JADU applications do not require a public hearing and are reviewed through the Building Permit process.  Requests for ADUs and JADUs are ministerial applications in accordance with the California Government Code, and will be approved if the proposed unit complies with the standards and requirements outlined in the City's Zoning Regulations.

The City’s Zoning Ordinance was most recently modified in 2019 (effective December 17, 2019), to comply with new state law.  For more information, contact the Duty Planner at or at 925-256-3558.

ADU and JADU Regulations


Contact the utility districts listed below for more information regarding connection fees for your proposed project.

Contra Costa Water District, Customer Service: (925) 688-8044

East Bay Municipal Utility District, New Business Office: (510) 287-1008

Central Contra Costa Sanitary District, Permit Team: 925-229-7371

For more information, contact the Duty Planner at or at 925-256-3558