How to get an ADU permit in San Diego (2026)

Who issues your ADU permit in San Diego

It depends on your address, not your ZIP code. Each city in San Diego County runs its own ADU permits under the same state law.

The rest of this guide covers the City of San Diego. State deadlines apply everywhere.

ADU requirements in San Diego

An ADU permit is ministerial: if the project meets the objective rules, staff must approve it without a hearing.

For the state rules behind these, see California ADU laws. New to the topic? Start with what an ADU is.

What to submit for an ADU building permit

The city's ADU bulletin points single-family projects to Section 2A of its Project Submittal Manual. A typical submittal includes:

• General Application (form DS-3032) and a Water Meter Data Card (DS-16).
• Site plan showing legal lot status, parking, setbacks and historic resource rules, drawn to the city's site plan bulletin.
• Architectural and structural plans: floor plans, elevations, framing and foundation.
• Title 24 energy calculations.
• Historical information if an existing structure is older than 45 years: a photo survey and the County Assessor's building record.

Your contractor or designer normally pulls the permit. If you're asked to sign as an owner-builder, the city has you sign form DS-3042, and you take on the contractor's responsibilities. Read how to hire an ADU contractor first.

Applying online

The City of San Diego takes ADU applications through its Development Services application portal: choose “Building Construction” under Building Applications. After you submit, you book a virtual appointment to get the permit issued.

How long does an ADU permit take?

State law sets the clock:

• 15 business days for the city to tell you whether the application is complete. If it doesn't, it's deemed complete.
• 60 days from a complete application to approve or deny. If the city does neither, the permit is deemed approved.
• A denial must come with a full list of what's wrong and how to fix it, and you can appeal.

The 60 days can be paused at your request, for example while you revise plans. The city posts a weekly snapshot of current intake and review times on its permit timeline page. Counting design, builders estimate 3 to 9 months before construction can start.

ADU permit cost in San Diego

Those totals come from a builder's published table, not the city's fee schedule; confirm yours with Development Services. What the law caps:

• Impact fees: none statewide for an ADU of 750 sq ft or less. The City of San Diego goes further and exempts the first two ADUs on a property from development impact fees, whatever their size.
• School fees: none for an ADU under 500 sq ft. Above that, San Diego Unified charges $5.38 per sq ft.
• Utility connection fees: none for an ADU converted from existing space.

Permit fees are a small part of the total. See what an ADU costs in San Diego.

Coastal development permit for an ADU

If your lot is in the Coastal Overlay Zone, most ADUs also need a Coastal Development Permit, and state law expects a decision within 60 days. The Coastal Commission certified the city's 2024 ADU rules for the coastal zone, but some later amendments were still awaiting certification, so coastal lots can be under older rules. Ask which version applies before you design.

Fire hazard zones

• Setbacks: in high and very high fire hazard severity zones, San Diego requires a 4-foot side and rear setback even for a low ADU.
• Construction: new buildings in fire hazard severity zones must use the state's wildfire-resistant construction rules (Chapter 7A).
• Sprinklers: an ADU needs them only if the main house is required to have them, and if the house has sprinklers, the ADU must too.

The 30-day pre-approved plan path

A detached ADU built from a plan the city has pre-approved, or identical to one it approved in the current code cycle, must be reviewed within 30 days. The City of San Diego accepts permit-ready plans from the County of San Diego and other agencies, though they must still meet the city's submittal rules. The County's free plans run from 600 to 1,200 sq ft and are about 85% complete. See pre-approved ADU plans in San Diego and ADU floor plans.

Conversions, JADUs and existing units

Not every ADU permit is for a new backyard building. The same ministerial process covers:

• Conversions. A garage or other existing space can become an ADU with no setbacks for the existing structure and no new utility connection required. San Diego doesn't require sprinklers when existing permitted space becomes an attached ADU.
• Junior ADUs. Up to 500 sq ft inside the house, which can include an attached garage. San Diego's code requires the owner to live on site. See our junior ADU guide.
• Unpermitted units. If an ADU was built without permits before January 1, 2020, the city can't deny a permit to legalize it unless a fix is needed for health and safety, and can't charge impact fees for it. You may get a confidential inspection from a licensed contractor before you apply. San Diego's process is in Information Bulletin 242.

Common reasons for corrections

We couldn't find published data on which corrections are most frequent. These are the items the city's own checklists call out, and the easiest to get wrong:

• Incomplete site plan. Missing lot status, setbacks to property lines and other buildings, or parking.
• No historical documentation for a house or garage older than 45 years.
• Missing energy calculations or forms like the Water Meter Data Card.
• Fire zone and sprinkler details that don't match the main house.
• Weak correction responses. The County, for example, wants revised sheets rather than hand edits, and won't accept vague answers.

The fastest fix is a complete first submittal. Ask your designer to check the plan set against the city's ADU bulletin and submittal manual before uploading, since the 60-day clock only starts once the application is complete.

Inspections and final

Once the permit is issued and work starts, each stage is inspected before it's covered up. In San Diego, passing the final inspection is your approval to occupy the ADU. Pick a builder with an active license: compare verified ADU builders in San Diego or check a contractor's license.

Common questions