Check your property's zoning, browse designs & get contractor estimates for your ADU project:
Last Updated 08/14/21
Number of ADUs allowed:
Under state law, each single-family home may now add at least one Accessory Dwelling Unit (ADU). Owner occupied single-family properties may add one Accessory Dwelling Unit (ADU) and one Junior Accessory Dwelling Unit. Multi-family properties, per every four existing residential units, may add one Accessory Dwelling Unit (ADU), so long as the existing units were legally established.
Types of ADUs allowed:
Detached ADU, Attached ADU, Junior ADU are allowed. Accessory Dwelling Units may be new construction or converted from existing space. JADUs must be converted from existing space.
ADU projects on single family or multi-family residential parcels will not be subject to the minimum lot size of the underlying local zoning code or by special ordinance. ~ AB68 & AB881 Update
Residential properties will be permitted to create up to 850 sqft for a one bed ADU or up to 1,000 sqft for a two bed ADU, regardless of the underlying zoning standards of the property. A Junior Accessort Dwelling Unit (JADU) is permitted up to 500 sqft. According to California Residential Code, the minimum size of any living unit is 150 sqft (including ADUs and Junior Accessort Dwelling Unit (JADU)s). ~ Updated: State Law AB-68
Setbacks for a detached new construction Accessory Dwelling Unit shall be no more than 4 feet from the rear and side lot lines. No setbacks shall be required for Accessory Dwelling Units and Junior Accessory Dwelling Unit (JADU)s converted from legally eastablished existing space. Attached new construction Accessory Dwelling Units and conversions from existing space to be expanded must comply with the setbacks of the underlying zone. ~ AB68
Lots which convert an existing garage to an Accessory Dwelling Unit or Junior Accessort Dwelling Unit (JADU) will not be subject to replacement parking requirements. ~ AB68 & AB881 Update
Accessory dwelling units shall not be required to provide fire sprinklers if they are not required for the primary residence and may employ alternative methods for fire protection. (State requirements)
Shape, materials and style:
State Standards don't specify design restrictions.
State Standards don't specify height restrictions.
State Standards don't require any additional design review.
Number of Bedrooms:
Not specified by State Standards.
Between between 2020 and 2025, owner occupancy requirements will not apply to new Accessory Dwelling Unit (ADU)s. (applicable to new construction and conversion units) ~ SB-13
Local health officer approval where a private sewage disposal system is being used, if required. (State requirements)
*** 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 645 sqft
43 ft x 15 ft
ADU Model 528 sqft
24 ft x 22 ft
ADU Model 792 sqft
38 ft x 24 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.