Check your property's zoning, browse designs & get contractor estimates for your ADU project:
Number of ADUs allowed:
Under state law, each single-family home may now build at least one Accessory Dwelling Unit. Owner occupied single-family properties may build one Accessory Dwelling Unit and one Junior ADU. Multi-family properties, per every four existing residential units, may build one Accessory Dwelling Unit, so long as the existing units were legally established.
Types of ADUs allowed:
Detached ADU, Attached ADU, Junior ADU are approved. ADUs may be new construction or converted from existing space. JADUs must be converted from existing space.
Single family and multi-family residential properties will not be subject to the minimum lot size of the underlying zoning district or by ordinance for ADU projects. ~ AB68 & AB881 Update
Residential parcels will be permitted to construct up to 850 square ft. for a one bedroom ADU or up to 1,000 square ft. for a two bedroom ADU, regardless of the underlying zoning standards of the property. A Junior Accessort Dwelling Unit (JADU) is permitted up to 500 square ft.. According to California Residential Code, the minimum size of any living unit is 150 square ft. (including Accessory Dwelling Units and Junior Accessort Dwelling Unit (JADU)s). ~ Updated: State Law AB-68
The maximum required setback for a detached new construction Accessory Dwelling Unit (ADU) shall be no more than 4 feet from the rear and side property lines. Setbacks will not be required for Accessory Dwelling Unit (ADU)s and Junior Accessory Dwelling Units converted from existing space that was legally eastablished. Attached Accessory Dwelling Unit (ADU)s and conversions from existing space to be expanded will be required to comply with the setbacks of the underlying zone. ~ AB68 & AB881 Update
Replacement parking shall not apply to lots which convert an existing garage to an Accessory Dwelling Unit or Junior Accessory Dwelling Unit. ~ AB68 & AB881 Update
Accessory dwelling units shall not be required to provide fire sprinklers unless they are also required for the primary dwelling. ~ State Standards
Shape, materials and style:
Specific design styles and restrictions are not specified under State Standards. Passageways shall not be required in conjunction with the construction of an accessory dwelling unit. ~ State Standards
The maximum height of an ADU is not specified in the state standards. If ADU maximum height is not established locally, the height limitations of the underlying zone shall apply. ~ State Standards
The municipality shall provide a ministerial review process which is not based on a discretionary approval for an ADU. The process shall take no less than 120 days. Valid applications submitted for ADUs, if not approved or denied within 120 days from submission, shall be considered approved. ~ State Standards
Number of Bedrooms:
No maximum number of bedrooms is established other than that implied by the maximum size of an ADU allowed. ~ State Standards
Owner-occupancy will not be required for new Accessory Dwelling Units (conversion and new construction) built between 2020 and 2025. ~ Updated: State Law SB-13
Connection and utility fees shall be reasonable, and shall not be disproportionately higher than those to develop primary dwellings, so as not to deter the development of ADUs. If a private sewage disposal system is used, such as a septic system, review and approval by a local health officer may be required. ~ State Standards
*** Beginning in 2020, according to state law, all residential zoning districts, including single-family and multi-family, are allowed to build Accessory Dwelling Units. ***
Residential Building Code:
The California Building Code (CBC) 2019 is adopted.
ADU Design Library
Browse hundreds of models to find the right fit for your property.
ADU Model 216 sqft
18 ft x 12 ft
ADU Model 1040 sqft
40 ft x 26 ft
ADU Model 765 sqft
31 ft x 31 ft
This estimate is based on recently completed projects in the area and is inclusive of all typical soft costs such as permitting, design and engineering fees.