Overview of Accessory Dwelling Units & Junior Accessory Dwelling Units 

Accessory Dwelling Units (ADUs) and Junior Accessory Dwelling Units (JADUs) are independent and semi-independent dwelling units with complete or partial provisions for sleeping, cooking, and sanitation. ADUs and Junior ADUs are allowed on properties with existing or proposed single-family dwellings. ADUs are also permitted on lots that are developed with an existing duplex or multi-family units.

Definitions

Accessory Dwelling Unit: An attached or a detached residential dwelling unit that provides

complete independent living facilities for one or more persons and is located on a lot with a

proposed or existing primary residence. It shall include permanent provisions for living, sleeping, eating, cooking, and sanitation on the same parcel as the single-family or multifamily dwelling is or will be situated.

Junior Accessory Dwelling Unit: A unit that is no more than 500 square feet in size and

contained entirely within a single-family residence. A junior accessory dwelling unit may include

separate sanitation facilities, or may share sanitation facilities with the existing structure.

Benefits of ADUs

• ADUs are an affordable type of home to construct in California because they do not require paying for land, major new infrastructure, structured parking, or elevators.
• ADUs can provide a source of income for homeowners.
• ADUs are built with cost-effective wood frame construction, which is significantly less costly than homes in new multifamily infill buildings.
• ADUs allow extended families to be near one another while maintaining privacy.
• ADUs can provide as much living space as many newly-built apartments and condominiums, and they're suited well for couples, small families, friends, young people, and seniors.

ADUs give homeowners the flexibility to share independent living areas with family members and others, allowing seniors to age in place as they require more care.

 ADU Permit and Plan Review Process

Step #1 Review the ADU Ordinance

Review the City’s ADU Ordinance here to learn where ADUs and JADUs are permitted, the number of units allowed, required site development standards, and the approval process.

Step #2 Apply for ADU or JADU

In accordance with Municipal Code Section 18.63.110, an application for a "zoning compliance statement" shall be completed and submitted to the City's Planning Department for review. Accessory dwelling units and junior accessory dwelling units shall be allowed by ministerial approval of a zoning compliance statement issued by the City Planner, without discretionary review or hearing, in all areas of Sand City that are designated for their use as specified in Section 18.63.030, provided the requirements outlined in Chapter 18.63 are met.

A zoning compliance statement shall be issued within 60 days from the date the City receives a completed application for an ADU or JADU if there is an existing single-family or multifamily dwelling on the lot, and provided all the applicable requirements of Chapter 18.63 are satisfied.

If an application for an ADU or JADU is submitted with a permit application to create a new single-family dwelling on the same lot as the application for an ADU/JADU, approval of the ADU/JADU may be delayed until the application for the new single-family dwelling is acted upon; but the ADU/JADU unit will still be considered ministerially without discretionary review or hearing. If the applicant for an accessory dwelling unit or junior accessory dwelling unit makes a request for a delay, the 60-day time period for a zoning compliance statement shall be tolled for the period of the requested delay.

Step #3 Architectural Review and Building Permit Review

The exterior architectural design of any proposed ADU or JADU shall be ministerially reviewed prior to issuance of a building permit in accordance with the provisions set forth in Municipal Code Chapter 18.63.

Building permits for ADUs and JADUs within a residential or mixed-use zone shall be approved and issued ministerially as provided in Municipal Code Section 18.63.080.

California Housing Finance Agency ADU Grant Program

The ADU Grant Program is designed to expand housing opportunities in California by helping homeowners offset pre-development costs associated with building an accessory dwelling unit. Eligible homeowners may receive grant funding to reimburse qualifying expenses incurred during the planning and permitting process. Check here to see if you’re eligible.

Resources

California Department of Housing and Community Development Accessory Dwelling Unit Handbook (Updated January 2025)

HCD Additional Resources