Accessory & Junior Accessory Dwelling Units

This image is an example of a Converted Garage, Detached Accessory Dwelling Unit (ADU), and Attached ADUAccessory Dwelling Units (ADUs) provide independent living facilities on a parcel with an existing or proposed primary residence. ADUs are allowed on all single-family or multi-family parcels. Junior Accessory Dwelling Units (JADUs) are no more than 500 square feet in size and contained entirely within an existing accessory structure or within an existing or proposed single-family residence. ADUs can be integrated within a residence, can be attached to a residence, can be converted from an existing garage or be a new detached structure.

The construction of ADUs/JADUs is one of many City strategies to increase housing supply and affordability citywide. In accordance with state law, the City has adopted the following regulations to make it relatively easy and less expensive to construct ADUs/JADUs:

  • A property with a Single Dwelling Unit may have both an ADU and a JADU
  • A property with Multiple Dwelling Units may have two detached ADUs and may convert habitable and non-habitable spaces to ADUs
  • There is expedited permit processing for ADUs up to 800 square feet in size, less than 16 feet tall, and at least 4 feet from a side and rear yard property line
  • ADUs up to 1,000 square feet permitted with additional review.
  • ADUs are permitted to encroach into side and rear yard setback areas
  • No covered parking is required for ADUs. No replacement covered parking is required for conversions of garages to ADUs
  • There are no City Development Impact Fees (PDF) for ADUs less than 750 square feet in habitable floor area. The Development Impact Fees for ADUs 750 square feet or larger are charged proportionately in relation to the habitable area of the primary unit.

The City's regulations for ADUs/JADUs can be found in City adopted ADU/JADU Ordinance 1101 (PDF).

Below is a summary of the City’s regulations and review processes that apply to ADUs/JADUs. 

ADU/JADU Review Process

The City has two review processes that apply to proposed ADUs and JADUs: Building Permit Review and Zoning Compliance Review. A summary of each process is provided below.

Building Permit Review

If a proposed ADU or JADU meets all the applicable requirements summarized in the following table, the ADU or JADU qualifies for a Building Permit Review, which is a streamlined review process.

Note: No ADU or grading related to construction of an ADU is permitted within two hundred feet (horizontal) of a General Plan designated ridgeline.

ADU Buliding spreadsheet for website _4-7-22 rev

Zoning Compliance Review

If a proposed ADU or JADU does not qualify for a Building Permit Review, it is subject to a Zoning Compliance Review. ADUs and JADUs subject to a Zoning Compliance Review have more restrictive development standards. These more restrictive standards are summarized in the following table below.

Note: No ADU or grading related to construction of an ADU is permitted within two hundred feet (horizontal) of a General Plan designated ridgeline.

ADU webpage - Zoning spreadsheet - 4.7.22

ADU/JADU Application Submittal Process

  1. Contact a planner at planning@sanjuancapistrano.org to ask any questions that you may have about the ADU/JADU standards summarized in the tables above.
  2. Submit conceptual plans to planning@sanjuancapistrano.org for a planner to provide you with a free preliminary plan review to confirm whether your proposed ADU qualifies for a Building Permit Review or a Zoning Compliance Review. In approximately one week you will receive an email from a Planner providing you with instructions for the next step.
  3. If a Planner determines that your proposed ADU qualifies for a Building Permit Review, you will be instructed to submit a permit application to the City's Building Division pursuant to the permit application submittal instructions described on the Building Division's webpage. Your submitted building permit application must include a completed and signed Accessory Dwelling Units Checklist (PDF).
  4. If a Planner determines that your proposed ADU does not qualify for a Building Permit Review, you will be provided with comments on how to amend your proposed ADU to qualify for a Building Permit Review and whether your ADU meets the Zoning Compliance Review standards. 
  5. If you opt to amend your plans to qualify for a Building Permit Review, repeat Step 2 above. If you opt not to amend your plans to qualify for a Building Permit Review and wish to apply for a Zoning Compliance Review, a Planner will provide you a Building Permit number and initiate a formal Zoning Compliance Review of your proposed ADU.
  6. A Planner will conduct a formal review of your ADU and if the code requirements for a Zoning Compliance Review are not being met, corrections will be provided to you. Corrections will need to be addressed and resubmitted planning@sanjuancapistrano.org for additional review. This step will need to be repeated until all code requirements for a Zoning Compliance Review are met.
  7. Once a Planner determines that your proposed ADU meets all the code requirements for Zoning Compliance Review, you will be asked to schedule an appointment with the Building Division, referencing the Building Permit number provided to you by a planner in Step Number 5 so you can submit a Building Permit application in accordance with the instructions described on the Building Division's webpage.

ADU Addressing

ADUs require their own address. The primary unit and the ADU must share the same numerical address with Unit Number #1 assigned to the main residence and Unit Number #2 assigned to the ADU. ADU applicants will be asked to submit an Address Assignment Request Form (PDF) as part of the Building Division's plan check process.

ADU Deed Restriction

A Deed Restriction (PDF) must be recorded against the title of the property prior to a building permit for construction of an ADU or JADU being issued.