CostolioADU (accessory dwelling unit) cost in San Diego
In San Diego, the median declared value on 5585 adu (accessory dwelling unit) permits issued to was $118,620, according to Development Permits - approvals issued (set 1) permit data (checked ).
ADU (accessory dwelling unit) cost in San Diego: permit figures
| Figure | Value |
|---|---|
| Median | $118,620 |
| 25th percentile | $67,720 |
| 75th percentile | $194,828 |
How this was counted
5585 permits · 2022-01-03 to 2026-10-30 · Source: Development Permits - approvals issued (set 1) · Filter: stream https://seshat.datasd.org/development_permits/approvals_issued_datasd.csv; APPROVAL_ISSUE_DATE >= 2022-01-01 ; rule: keyword /\bJ?ADUS?\b|ACCESSORY DWELLING|GRANNY|SECOND(ARY)? (DWELLING )?UNIT/ AND /NEW|CONSTRUCT|CONVER|BUILD|ADD|CREAT|ESTABLISH|DETACHED|ATTACHED/ AND NOT /SOLAR|\bPV\b|WATER HEATER|RE-?ROOF|PANEL UPGRADE|\bEV\b|(REPAIR|REMODEL|ALTERATION)S? (TO|OF|IN) (AN |THE )?(EXISTING|EXIST\.?|\(E\)) (J?ADU|ACCESSORY)|LEGALIZ|REVISION|SUPPLEMENT/ ; cost>0 ; approvals deduped to PROJECT_ID (max valuation) · Pulled: 2026-11-02T14:19:22-08:00 · Checked on: 2026-11-02
What a adu (accessory dwelling unit) permit usually covers
Building a new accessory dwelling unit, or converting a garage or other space into one. Usually the new unit's structure, foundation, framing, plumbing, electrical and mechanical work the city inspects. Site work, utility connection fees, design fees, appliances and furnishings are often priced or listed separately.
ADU (accessory dwelling unit) in San Diego compared with other places
Among the 3 places where we have adu (accessory dwelling unit) figures, San Diego has the median at position 3 from lowest. Lower medians: Los Angeles, Richmond. San Diego has the highest median of these.
Other San Diego projects with figures: Seismic retrofit (foundation).
Read this first. Permit values are self-reported by the applicant to set permit fees. They often leave out materials or labor, and they are not what the contractor actually charged. A quote above or below this range can be reasonable.
About this San Diego sample
- 5585 permits after dropping $0 or blank values (12% of keyword matches had no cost)
- cost field
APPROVAL_VALUATIONin Development Permits - approvals issued (set 1) - permits issued 2022-01-03 to 2026-10-30
ADU (accessory dwelling unit) permits in San Diego by year
1,348 of these permits were issued in 2024, the busiest year in this sample. Counting only full years, the number of permits went up in 2023, then about the same in 2024, then down in 2025. The median declared value went about the same in 2023, then up in 2024, then up in 2025. 2022 and 2026 are partial years here, so their counts are lower.
| Year issued | Permits | Median |
|---|---|---|
| 2022 | 774 | $99,294 |
| 2023 | 1,297 | $98,879 |
| 2024 | 1,348 | $118,206 |
| 2025 | 1,218 | $133,788 |
| 2026 | 948 | $141,865 |
By month issued, the busiest months were April, May, October, and the quietest were December, November, September.
What the San Diego adu (accessory dwelling unit) permits describe
We read the description each applicant wrote, leave out the standard wording the city adds to every permit, and sort the permit by the words it uses. The permit type the city chose is not used here. Where the description does not say, we count it as not stated. The most common kind here is detached ADU.
- Detached ADU: 2,218 permits (40%), median $146,952
- Garage conversion ADU: 1,431 permits (26%), median $77,865
- Junior ADU: 685 permits (12%), median $76,308
- ADU, type not given: 632 permits (11%), median $137,610
- Attached ADU: 613 permits (11%), median $124,511
- Not stated in the description: 6 permits (0%)
Other work listed on the same San Diego permits
Out of 5,585 San Diego adu (accessory dwelling unit) permits with a description of their own, 591 (11%) also mention electrical work; 459 (8.2%) also mention plumbing; 437 (7.8%) also mention mechanical or HVAC; 192 (3.4%) also mention windows or doors; 74 (1.3%) also mention structural or framing.
How we matched adu (accessory dwelling unit) permits in San Diego
San Diego has no permit type for this work, so we count a permit when its description mentions ADU, junior ADU, accessory dwelling or second unit, with words like new, build or convert. We leave out permits whose description mentions solar, solar panels, water heaters, reroofing, panel upgrades, EV chargers, repairs or remodels of an existing ADU, legalizing existing work, permit revisions or permit supplements. We keep only permits with a declared value above $0. San Diego lists several approvals for one project, so we keep one row per project.
ADU (accessory dwelling unit) across Southern California
Putting together every adu (accessory dwelling unit) permit on a published page in Southern California (Los Angeles, San Diego) gives 38,870 permits with a combined median of $75,000. San Diego supplies 14% of them, and its own median is 58% higher than the combined one. Each place covers its own dates, so treat this as a rough guide.
Counted from the same 5585 permits as the figures above (2022-01-03 to 2026-10-30). Source: Development Permits - approvals issued (set 1).
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Updated