A Streamlined, Ministerial Permit Process.
San Diego reviews ADU applications ministerially, meaning no discretionary review and no public hearings. The city is required to respond to a complete submission within 60 days, and most permits are approved in three to four months. The city publishes applicant guidance through its Development Services information bulletins.
Those local rules sit on top of the baseline entitlements every California homeowner gets under state ADU law, and San Diego has adopted additional standards and bonuses that go beyond those minimums.
Size And Height Limits.
Detached ADUs must be at least 150 square feet and can reach 1,200 square feet. Height is 16 feet by right, rising to 18 feet if the lot sits within a half mile of a major transit stop or on a multifamily property, and up to 20 feet when the roof pitch matches the primary home.
Attached ADUs follow the same 150 to 1,200 square foot range but can go up to 25 feet tall, or the zoning height limit if that is lower. Junior ADUs (JADUs) run 150 to 500 square feet and must be created inside the existing or proposed single-family home. The full standards live in Chapter 14 of the San Diego Municipal Code.
Setbacks, Parking, And Coastal Considerations.
Front and street-side setbacks follow the base zone. Rear and side setbacks drop to 4 feet for ADUs taller than 16 feet, and can shrink to 0 feet for single-story units under 16 feet, subject to fire code. Conversions and rebuilds within an existing structure's footprint have no setback requirement at all.
Most San Diego ADUs need no new parking. The main exception is the Beach Impact Area of the Coastal Overlay Zone, where a new detached ADU may need one space unless it is near transit, under 500 square feet, part of the main home, or otherwise exempt. Converting a garage never triggers replacement parking, and JADUs never require parking. Extra review can apply in the Coastal Overlay Zone and mapped Areas of Future Sea Level Rise.
One quirk worth planning for: build two or more ADUs (JADUs included) and the city requires trees, at least one per property plus two for every 5,000 square feet of lot area, chosen from the city's approved list.
How Many Units You Can Build.
A single-family lot can host one detached ADU, one conversion ADU inside the main house or an existing structure, and one JADU. Not sure what your lot allows? Check your lot and we will map it for you.
Multifamily lots go much further: up to eight detached ADUs (capped at the number of existing units), unlimited ADUs carved out of non-habitable interior space like storage rooms or garages, and conversions of up to 25% of the existing habitable units. If your building is still under construction, two detached ADUs are allowed in the meantime. See how Abodu handles multifamily ADU projects.
San Diego also rewards affordability: deed-restrict a unit at affordable rents for 10 to 15 years and you earn one bonus ADU. Inside Sustainable Development Areas near transit, there is no cap, as long as every bonus unit is matched with an affordable one.
What It Actually Costs.
Custom site-built ADUs in California routinely exceed $250,000 before change orders, and the final number often is not known until construction is already underway.
Abodu works differently: transparent published pricing: homes from $234,800 plus a published installation price, an expected all-in from $298,800 that covers design, permits, the factory build, delivery, and installation. See how the process works from first call to move-in.