Accessory Dwelling Units (ADUs)

ADU Icon                                                                                                                                     Accessory Dwelling Units (ADUs)

What is an accessory dwelling unit?

An ADU is an accessory dwelling unit with complete independent living facilities for one or more persons and has a few variations:

  • Detached: The unit is separated from the primary structure.
  • Attached: The unit is attached to the primary structure.
  • Converted Existing Space: Space (e.g., master bedroom, attached garage, storage area, or similar use, or an accessory structure) on the lot of the primary residence that is converted into an independent living unit.
  • Junior Accessory Dwelling Unit (JADU): A specific type of conversion of existing space that is contained entirely within an existing or proposed single-family residence.

adus types image(Adapted from the ABCs of ADUs)

On January 1, 2020, new State law took effect to create opportunities for accessory dwelling units (ADUs) and junior accessory dwelling units (JADUs) at single-family dwellings (CA Gov’t Code section 65852.2). Beyond traditional market rate construction and affordable housing developments, ADUs provide an alternative, flexible housing model that can help address home supply and affordability in California.

 ADUs and JADUs are separate from the recently adopted State law known as SB 9 (CA Gov’t Code section 65852.21), effective January 1, 2022. In some situation, but not all, it may be possible to have two principal units through SB 9, as well as an ADU/JADU. Learn more about building housing units and lot splits through SB 9.

What is the permitting process for constructing an ADU/JADU?


The ADU approval is “ministerial” or administrative. The first step in the permitting process for constructing an ADU/JADU is to obtain approval from the Planning Division, then obtain a building permit from the Building Division.

Person IconWhere to start?

Please review the Planning ADU Handout for helpful information regarding the zoning requirements for ADUs as well as the ADU Application Checklist to make sure you are submitting a complete application. Once Planning approval has been received, you can move forward with the building permit. You may submit simultaneously to both the Planning Division and Building Division, however, the Planning project must be approved prior to any building permit being issued.

What funding is available to assist homeowners to build an ADU?

Although there is currently no funding from the City of Richmond available to assist homeowners in constructing an ADU, there are other resources that homeowners may review for funding assistance. The California Department of Housing and Community Development has an ADU webpage that includes a section of ADU Funding for Homeowners that the State updates.

One example is the CalHFA’s ADU Grant Program, effective on or after September 20, 2021, the CalHFA ADU Grant Program will provide up to $25,000 in assistance to reimburse homeowners for predevelopment costs necessary to build and occupy an ADU.

Further Questions

For further inquiries regarding the Planning Division’s permit process, please call 510-620-6706 or email For further inquiries regarding the Building Division’s permit process, please call 510-620-6868 or email Refer to the eTRAKiT Portal Help Guides for technical assistance on submitting your application online.