In short
- 8,425 ADU permits since 2018.
- 1,445 in 2025, down 4% from 2024.
- Typical permit time: 224 days from application to permit (median of 8,392 permits with both dates recorded).
- Most common kind: detached ADUs (43% of permits with a known type).
- Median declared value: $89,662 (declared values understate the full cost).
About this data
- 2018 onward: City of San Diego Development Services Department permits that create an ADU or junior ADU. Build type is classified automatically from permit descriptions (see each record's confidence).
- Costs are declared permit valuations (single-ADU permits only), not final construction costs.
- The city closes a permit both after its final inspection and after it expires, and its data doesn't say which, so this page doesn't estimate how many permits were finished. Closed permits stay in the counts.
Permits by year
Permits by year and type (table)
| Year | All ADU permits | Garage conversions | Detached |
|---|---|---|---|
| 2018 | 242 | 54 | 74 |
| 2019 | 508 | 131 | 169 |
| 2020 | 565 | 130 | 201 |
| 2021 | 757 | 179 | 264 |
| 2022 | 775 | 206 | 253 |
| 2023 | 1,331 | 302 | 420 |
| 2024 | 1,500 | 302 | 484 |
| 2025 | 1,445 | 308 | 426 |
| 2026 so far | 1,302 | 221 | 377 |
“—” means the source for that year does not report ADU type.
Read more: ADU types explained
Not counted above: 87 approved projects with no building permit reported yet.
Not counted: 828 expired or cancelled permits.
ADU Bonus Program
San Diego's ADU Home Density Bonus Program lets owners build extra “bonus” ADUs beyond what state law allows, in exchange for an equal number of ADUs rented at income-restricted rents for 10 to 15 years. Rules in effect since August 22, 2025 (outside the Coastal Zone) allow more than one bonus ADU only near major transit, keep the program out of the city's largest-lot single-family zones, and cap the total ADUs on a single-family lot at 4 to 6 by lot size. In 2025, 194 of the city's 1,445 ADU permits (13%) included a bonus ADU.
| Year | ADU permits | With a bonus ADU | Share |
|---|---|---|---|
| 2023 | 1,331 | 30 | 2% |
| 2024 | 1,500 | 138 | 9% |
| 2025 | 1,445 | 194 | 13% |
| 2026 so far | 1,302 | 211 | 16% |
Permits whose city record lists at least one bonus ADU; the city records this from 2023 on. Sources: Municipal Code § 141.0302 · Information Bulletin 400.
ADU rules in San Diego
State law check: HCD found the city's 2025 ADU ordinance (O-21989) out of line with state law (October 6, 2025), on fire sprinklers, ADU size on apartment lots, fire setbacks and separate sale. The city responded; HCD hasn't posted a follow-up.
| Rule | San Diego's code | State law guarantees |
|---|---|---|
| Maximum size | 1,200 sq ft, attached or detached; at least 150 sq ft. No cap for an ADU inside the house or an existing accessory structure. One ADU up to 800 sq ft is allowed even over the floor-area limit. Junior ADU 150 to 500 sq ft. | At least 850 sq ft (1,000 sq ft with 2+ bedrooms) must be allowed; an 800 sq ft detached ADU always is. Conversions of existing space have no size cap. Junior ADU: up to 500 sq ft. |
| Height | Single-family lots: detached ADUs (and ADUs attached to an accessory structure) up to 2 stories, within the zone's height limit. | Detached: at least 16 ft (18 ft within ½ mile of transit, plus 2 ft for a matching roof). Attached: 25 ft or the zone's limit, whichever is lower. |
| Setbacks | Front setback of the zone (one ADU up to 800 sq ft may encroach). Street side 4 ft or the zone's, whichever is less. Interior side and rear: none up to 16 ft tall; over 16 ft next to homes, 4 ft or the zone's if less; 4 ft in High or Very High Fire Hazard Severity Zones. Conversions keep existing setbacks. | No more than 4 ft side and rear; none for conversions of existing space. |
| Parking | None, except 1 space per ADU in the Beach Impact Area of the Parking Impact Overlay Zone outside a transit priority area (with exemptions, such as 500 sq ft or less, or attached). Bonus-program ADUs: 1 space each outside a transit priority area. | At most 1 space; none within ½ mile of transit and in several other cases. No replacement parking when a garage is converted. |
| Owner living on site | None for ADUs. Junior ADU: the owner lives in the house or the junior ADU, under a recorded agreement. | None for ADUs. A junior ADU that shares a bathroom with the house requires the owner to live in one of them. |
| How many on a single-family lot | One ADU inside the house or an existing accessory structure, one attached or detached ADU and one junior ADU. The ADU Home Density Bonus Program can add affordable and bonus ADUs, up to 4, 5 or 6 ADUs and junior ADUs in all, by lot size (8,000 sq ft or less, up to 10,000, larger). | One ADU converted from existing space, one junior ADU and one new detached ADU (up to 800 sq ft). From January 1, 2027: two new detached ADUs (a city then needn't allow a junior ADU on that lot). |
| Short-term rentals | ADUs: 31 days or more. The code sets no term for junior ADUs; the city's bulletin says more than 30 days. | No guarantee: cities may require rentals of more than 30 days, and junior ADUs can't be short-term rentals. |
- ADU Home Density Bonus Program (SDMC 141.0302(d)), reformed by O-21989 (adopted July 23, 2025, effective August 22, 2025): not available in the RS-1-1, -2, -3, -4, -8, -9, -10 and -11 zones unless the lot is in a High or Highest Resource CTCAC Opportunity Area and planned Residential. Inside a Sustainable Development Area, one bonus ADU per deed-restricted affordable ADU; outside it, at most one bonus ADU and one affordable ADU.
- The code uses the Sustainable Development Area (walking distance to a major transit stop) to set how many bonus ADUs are allowed, and the transit priority area only for parking. Some city pages mix the two terms up; the code text controls.
- Bonus-program ADUs need fire sprinklers and pay a Community Enhancement Fee; in fire hazard zones the lot needs two evacuation routes and can't be on a cul-de-sac.
- Coastal Overlay Zone: most ADUs need a Coastal Development Permit, and the 2023 to 2026 ADU amendments (including the bonus-program reform) don't apply there until the Coastal Commission certifies them.
- ADUs can be split off and sold as condominiums (SDMC 141.0302(f)).
- Fees: development impact fees, school fees and the General Plan Maintenance Fee apply; pre-approved ADU plans get a 30-day review.
Where local rules conflict with state law, state law controls. Sources: San Diego Municipal Code 141.0302 (9-2026) · DSD Information Bulletin 400 (January 2026) · Ordinance O-21989 (July 23, 2025) · HCD findings (October 6, 2025) · HCD letter on the ADU bonus program (June 13, 2025); HCD's list of review letters; California ADU rules. Verified Oct 5, 2026. Rules change and every lot is different: confirm with the city before you design.
How long permits take
| Type | Median days, application to permit | Middle half | Permits |
|---|---|---|---|
| Detached ADU | 230 | 146 – 365 | 2,659 |
| Attached ADU | 204 | 123 – 355 | 1,197 |
| Garage conversion | 186 | 107 – 328 | 1,828 |
| Junior ADU (JADU) | 176 | 110 – 285 | 513 |
| Unclassified | 274 | 166 – 437 | 2,195 |
Middle half: the range covering the middle 50% of permits (a quarter were lower, a quarter higher).
Read more: How long ADUs take to build
What neighbors declared as cost
| Type | Median declared value | Middle half | Permits |
|---|---|---|---|
| Detached ADU | $121,493 | $79,323 – $155,583 | 2,135 |
| Attached ADU | $94,432 | $61,908 – $150,309 | 993 |
| Garage conversion | $59,434 | $42,619 – $86,874 | 1,524 |
| Junior ADU (JADU) | $55,842 | $41,656 – $75,390 | 455 |
| Unclassified | $111,827 | $69,916 – $163,294 | 1,343 |
Declared permit valuations often understate real construction cost.
Read more: How to choose an ADU builder
An ADU builder serving San Diego? Feature your business on this page.
Questions about ADUs in San Diego
How many ADUs have been permitted in San Diego?
Public records show 8,425 ADU permits in San Diego from 2018 through Nov 4, 2026. 1,445 in 2025, down 4% from 2024.
How long does an ADU permit take in San Diego?
Among the 8,392 ADU permits in San Diego with both dates recorded, half were issued within 224 days of the application; the middle half took 132 to 374 days. That includes plan-check corrections and resubmittals, not just the review itself.
How much does an ADU cost in San Diego?
The median value owners declared on ADU permits in San Diego was $59,434 for garage conversions and $121,493 for detached ADUs. Declared values often leave out design, fees and site work, so get several builder quotes.
Can I build an ADU on my property in San Diego?
California law allows ADUs on most lots with a house, including in San Diego, but what you can build depends on your lot, local rules and utilities. This site shows permits, not eligibility. See California ADU rules.
Where do I apply for an ADU permit in San Diego?
Apply with the City of San Diego Development Services Department, online through its Development Services Application Portal (Building Construction). Official ADU page.
How current is this?
- City of San Diego permits: through Nov 4, 2026 (published daily)
- State annual progress reports: through 2025 (published once a year)
How our data works · Download the data · Free to reuse with credit to SoCal ADU Tracker (socaladutracker.com), under CC BY 4.0.