Building an ADU in San Diego
Most San Diego ADU permits are reviewed by the City of San Diego Development Services Department. Lots inside the Coastal Overlay Zone, such as parts of Ocean Beach, Pacific Beach and La Jolla, can trigger coastal review, so confirm that early because it affects the schedule more than almost anything else.
The city has also run its own ADU bonus rules for lots near transit, and those rules have been revised more than once. If you are hoping to build more than one ADU, ask about the current rules for your specific address before any design work starts.
Older neighborhoods bring older garages. Many were built on thin slabs without footings, with undersized electrical service and no insulation. A conversion can still be the most cost-effective route, but the existing structure has to be assessed honestly before it is priced.
What state law allows
State ADU law sets the baseline in San Diego, and the city adds its own rules on top. On most single-family lots the state allows one ADU plus one junior ADU, and a complete application that meets the rules must be reviewed within 60 days.
- Converting a garage to an ADU generally does not require you to replace the lost parking spaces.
- Owner-occupancy is no longer required for a standard ADU. A junior ADU still requires the owner to live on the property.
- ADUs under 750 square feet are exempt from impact fees, and units of 500 square feet or less are generally exempt from school fees.
- Detached ADUs typically need only 4-foot side and rear setbacks.
Garage conversion or detached ADU on a San Diego lot?
Older San Diego neighborhoods often have a detached garage at the back of the lot, sometimes on an alley. Converting it is usually the faster and lower-cost route because the walls, roof and slab already exist, and an alley can give the unit its own entrance.
The slab and framing decide whether that holds. Where the garage is too small or too far gone, a new detached ADU in the rear yard costs more but is not held back by the old building's ceiling height, layout or energy performance.
How an All Pro Contractor ADU project runs
- Site visit to review the garage or yard, access, utilities and the goals for the unit.
- Written estimate covering the scope discussed, with design, engineering and permit responsibilities spelled out.
- Plans and permit submittal, either through our design partners or with plans you already have.
- Construction: foundation or slab work, framing, utilities, insulation, drywall, finishes and final inspection.