What You’re Allowed to Build in
County of San Diego ADU Local Zoning Laws
KEY RULES AT A GLIMPSE
Size and Separation
Maximum size: 1200 sqft
Side/rear setbacks: 4 feet
Two story: Yes
Building separation: 6 feet
Additional Requirements
Soils Report: No
Building Verification Survey: No
Coastal permit (in some areas): No
Stormwater Mitigation: No
Regulations for Accessory Dwelling Units
Permission for ADU
Yes
Zoning Districts Permiting ADUs
ADUs are allow in existing or proposed single-family dwelling (SFD) in a residential or mixed-use zone.
Maximum Size of ADU
The total floor area of an attached ADU shall not exceed 50% of the SFD’s floor area, up to a maximum of 1,200 square feet.
ADU can be up to 850 square feet or 1,000 square feet for ADUs with more than one bedroom, regardless of the existing SFD’s size.
Maximum Height of ADU
A detached ADU is limited to 25’ in height.
Setbacks of the ADU
A minimum setback of 4 feet from the side and rear lot lines is required for an ADU constructed above a permitted detached accessory structure.
For a corner lot, the exterior side yard setback must be at least 4 feet from the edge of the easement, street, or property line.
All newly constructed detached and/or attached ADUs must comply with the required front yard setbacks and have a minimum side and rear setback of at least 4 feet.
Parking Regulations of ADU
An ADU shall provide one parking space, which may be located within the setbacks and in an existing driveway as tandem parking.
Parking spaces don’t need to be replaced when a garage, carport, or covered parking structure is demolished for ADU construction or converted into an ADU.
A parking space is not required for the ADU if it is located within one-half mile of public transit or within a historically significant historic district.
Additional Notes
The ADU is either attached to an existing SFD or detached and on the same legal lot.
Separate sale or ownership of an ADU is prohibited unless the lot is subdivided, creating a separate lot for each dwelling.
Converting a guest living quarters, accessory living quarters, or accessory apartment into an ADU is potentially permitted and requires approval of a building permit.
The ADU shall not be used or rented for less than 30 days.
Properties with multiple existing, non-conforming SFDs in a residential zone that only allows one SFD can have an ADU, but a JADU is not allowed.
Municipal Department Contact Details
Department: County Communications Office
Contact Details
Contact Number: (619) 595-4633
Email: communications@sdcounty.ca.gov
Address: 1600 Pacific Highway, Rm 208, San Diego, CA 92101
Regulations for Junior Accessory Dwelling Units
Permission for JADUs
Yes
Zoning Districts Permiting ADUs
JADUs are allow in existing or proposed single-family dwelling (SFD) in a residential or mixed-use zone.
Maximum Size of ADU
A JADU shall not exceed 500 square feet.
Setbacks of the ADU
JADU’s must comply with main building setbacks.
Parking Regulations of ADU
No additional parking space is required for a JADU.
Additional Notes
A JADU may include separate sanitation facilities or share sanitation facilities with the existing structure.
When an existing garage, carport, or covered parking space is demolished or converted into a JADU, the two required parking spaces must be replaced.
A JADU must be within an existing or proposed SFD and cannot be attached to an ADU.
The JADU may be rented, but not for less than 30 days.
JADU is not intended for sale separate from the primary residence.
The owner is required to live in one of the two units.
Application Process for Accessory Dwelling Unit Permit
Step 1: Explore and estimate fee costs.
Step 2: Obtain evidence of a legal lot and consult with relevant departments for requirements.
Step 3: Prepare plot plan and two complete sets of building plans and supporting documents.
Step 4: Prepare grading plans if required.
Step 5: Obtain Building Plan Pre-Submittal Review (BPPR) approvals.
Step 6: Schedule an appointment for project submittal or process minor projects over the counter (OTC).
Step 7: Complete Building Permit Application and, if applicable, Grading Permit Application.
Step 8: Submit building plans and permit application.
Step 9: Receive plan check fee invoice and pay plan check fees.
Step 10: Read all documents received at plan submittal and complete conditions of approval.
Step 11: Obtain required clearances as specified by conditions of approval.
Step 12: Plans are reviewed by County staff for compliance.
Step 13: Correct noted deficiencies and prepare a response list.
Step 14: Return corrected plans and response list for recheck.
Step 15: Repeat steps 9-12 until all corrections are approved.
Step 16: Submit plans to applicable fire district for review and approval if not reviewed by County Fire Marshal.
Step 17: Return signed-off correction lists and approved plans to Building Division.
Step 18: Permit invoice is issued and pay applicable fees.
Step 19: Permit is issued and receive building permit, approved plans, and Inspection Record card.
Step 20: Commence construction and call for inspections.
Step 21: Request inspections periodically to keep the permit active.
Step 22: Submit and obtain approval for any changes to the project.
Step 23: Pass all required inspections to obtain Certificate of Occupancy.
Fees for Construction of ADU
| Permit Type | Plan Review Fee | Permit Fee |
| Accessory Dwelling Unit for OTC Review | $994 + $0.279/sf | $1,444 + $0.486/sf |
| Electrical Only | $337 | |
| Plumbing Only | $337 | |
| Mechanical Only | $337 | |
| Electrical, Plumbing and Mechanical | $631 | |