Check your property's zoning, browse designs & get contractor estimates for your ADU project:
Last Updated 09/20/21
City Hint: The City of Lancaster permitted a total of 28 ADU projects in the past year of 2020.
Number of ADUs allowed:
Under state law, each single-family home may now create at least one Accessory Dwelling Unit. Owner occupied single-family properties may create one Accessory Dwelling Unit and one Junior Accessory Dwelling Unit (JADU). Multi-family properties, per every four existing residential units, may create 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.
Accessory Dwelling Unit projects on single family or multi-family residential lots will not be subject to the minimum lot size of the underlying local zoning code or by special ordinance. ~ According To AB68
Single-family and multi-family Properties will be permitted to add up to 850 sq. ft. for a one bedroom ADU or up to 1,000 sq. ft. for a two bedroom ADU, regardless of the underlying zoning standards of the property. A Junior ADU up to 500 sq. ft. is permitted. The minimum size of any living unit (including Accessory Dwelling Units and Junior ADUs) is 150 sq. ft. according to California Residential Code. ~ AB68
Detached units may be allowed up to 1,200 sq. ft.
Setbacks for a detached new construction Accessory Dwelling Unit shall be no more than 4 ft 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. ~ AB-68
Properties which convert an existing garage to an ADU or JADU will not be subject to replacement parking requirements. ~ According To AB68
A local agency shall not impose ADU parking standards for any of the following
(1) Accessory dwelling unit is located within one-half mile walking distance of public transit.
(2) Accessory dwelling unit is located within an architecturally and historically significant historic district.
(3) Accessory dwelling unit is part of the proposed or existing primary residence or an accessory structure.
(4) When on-street parking permits are required but not offered to the occupant of the accessory dwelling unit.
(5) When there is a car share vehicle located within one block of the accessory dwelling unit.
Fire sprinklers shall not be required for the ADU unless they are also required for the primary unit.
Shape, materials and style:
The accessory dwelling unit shall be architecturally compatible with the primary dwelling unit.
ADUs shall be allowed at least 16 ft in height. 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
Application. Any property owner seeking a permit for an accessory dwelling unit shall submit a director's review application. The director shall approve the application so long as the accessory dwelling unit complies with all provisions of this section. In the event such application is denied, the appeals proceedings set forth in chapter 2.44 shall be available to the applicant. According to state law, the application shall be approved though a ministerial process and a determination shall be made within 120 days of filing.
Number of Bedrooms:
Not specified by State Standards.
Owner-occupancy will not be required for new ADUs (conversion and new construction) built between 2020 and 2025. ~ According To SB13
The accessory dwelling unit may have separate utility meters from the primary dwelling unit, such as meters for water, gas and electricity.
*** Beginning in 2020, according to state law, all residential zoning districts, including single-family and multi-family, are allowed to build Accessory Dwelling Units. ***
The accessory dwelling unit may be constructed as a detached building or may be attached to the primary residence on a lot or parcel in the RR or R Zone.
Conversions. In order to legitimize an illegal accessory dwelling unit to a conforming legal accessory dwelling unit, the property owner shall file a director's review application and shall comply with the standards and requirements set forth in this section. The director reserves the right to allow deviations, if there is a demonstrated difficulty or impracticality to modify the accessory dwelling unit to meet adopted requirements; nonetheless, all code requirements pertaining to fire and building safety must still be met.
Residential Building Code:
The California Building Code (CBC) 2019 is adopted.
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.