City of San Diego ADU rules: size, setbacks, parking and permits. Check the rules for your property.
Official City guidance reviewed October 24, 2026. General planning information—not a site assessment or permit approval. Header: illustrative AI-generated San Diego cityscape.
La Mesa and other incorporated cities have their own rules; this guide does not cover all of San Diego County.
The City's Information Bulletin 400 is the starting reference. Your zoning, existing development, proposed unit type, and any coastal or fire-hazard conditions determine which provisions apply.
City guidance lists a maximum of 1,200 square feet for a new attached or detached ADU. Floor-area, base-zone and other applicable requirements still matter. Existing-space conversions have separate provisions and are not subject to that same 1,200-square-foot limit.
Base-zone and overlay height limits apply. On lots that allow single-dwelling but not multi-dwelling development, detached ADUs and ADUs attached to an accessory structure are limited to two stories. Do not assume a universal 24-foot limit.
Some side and rear encroachments are allowed, but height, neighboring residential uses, building/fire codes and overlays affect the result. A structure above 16 feet next to residential use generally needs four-foot side/rear setbacks or the smaller base-zone setbacks. Very High Fire Hazard Severity Zone sites have at least four-foot side/rear setbacks; fire or brush-management requirements may require more.
The City generally does not require ADU parking outside the Coastal Overlay Zone. Within the coastal Beach Impact Area, outside a transit priority area, parking can be required unless an exemption applies. Garage replacement-parking rules also have coastal exceptions.
A JADU is no more than 500 square feet and is located within qualifying single-dwelling space or an attached garage. It needs a separate exterior entry and a kitchen or efficiency kitchen. Occupancy and agreement rules are distinct from an ADU, with exceptions including separate sanitation facilities; confirm applicable coastal provisions.
City guidance does not require on-site owner occupancy for an ADU and prohibits ADU leases shorter than 31 consecutive days. JADUs have separate conditions and cannot be used for short-term residential occupancy. Review deed restrictions and other applicable requirements before relying on a rental plan.
The City's bulletin explicitly warns that some regulations are not effective within the Coastal Overlay Zone until the relevant ordinances receive Coastal Commission certification. An inland summary is not enough for a coastal parcel.
A Coastal Development Permit may be needed depending on the proposed work, with exemptions for certain qualifying projects. Check the parcel's base zone and overlays before settling on a design.
Look Up City Zoning and Parcel Information ↗A building permit is required to create an ADU or JADU. Typical submittals include a site plan, floor/roof plans, elevations, structural documents and energy calculations, as applicable. Utility routing, access and existing structures need project-specific attention.
Pre-approved plans can provide a starting point, but the property still needs applicable development review and a permit. Fees depend on the proposal and applicable exemptions; do not assume an ADU is exempt from every charge or that a review period guarantees a construction start.
For an early budget reference, use the ADU price calculator for a broad preliminary planning range. A quote requires confirmed scope and site review.
No. Both operate within California's ADU law framework, but they are separate jurisdictions with their own development standards and review processes. Use the rules for the city governing your parcel—not just its mailing address.
City guidance describes combinations of new ADUs, existing-space conversions and JADUs, plus separate multi-dwelling and density-bonus provisions. The allowed combination depends on existing development, zoning and the proposed permit path; review your property before assuming a unit count.
Bring your address, intended use and room priorities. Existing plans, surveys and photos can help if you have them, but you do not need to commission new documents just to book an introductory conversation. The call is not a feasibility report or approval.
No. County Planning & Development Services governs unincorporated areas; other incorporated cities have their own departments. Confirm your actual jurisdiction before using a local regulation summary.
Reviewed October 24, 2026. Rules can change; the official City requirements and applicable state law govern your project.
Talk with CRS about your goals, the property questions to investigate, and the next planning step. Free 30-minute video consultation; no obligation to build.
Book a Free Consultation →Local rules, overlays, and parcel conditions can affect a project. This general guide is not an approval. Confirm current requirements with your jurisdiction before designing around them.
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