ADUs in City of San Diego, CA
✓ Verified November 1, 2026 Rules, fees, and timelines below were verified November 1, 2026. Anything marked “confirm” or “to verify” is still open.
A mailing address that says “San Diego” does not guarantee the parcel is under City of San Diego rules — some parcels fall under County rules. Confirm jurisdiction before relying on anything on this page.
Coastal split: the 2025 rules described here have been effective outside the Coastal Overlay Zone since August 22, 2025. Inside the coastal zone, Coastal Commission certification is still pending (anticipated 2026), and the older rules currently apply there.
Does it apply to my lot? — address check
Enter a San Diego County street address. The checker geocodes it and checks public transit stops nearby. Privacy: your typed address goes directly from your browser to OpenStreetMap's free Nominatim geocoder and the public SanGIS transit-stops layer. It never touches an ADUKey server — ADUKey has no server endpoint for this, so there is nothing to send it to.
Parking-exemption rule: no parking required within a 1/2-mile walking distance of public transit (bus stops included). Straight-line distance is measured first: a straight-line miss is definitive, a straight-line hit is provisional until the walking route is checked.
What you can build
| Rule | What applies | Note |
|---|---|---|
| Per-lot cap, lot ≤ 8,000 sq ft | Max 4 ADUs | |
| Per-lot cap, lot 8,001–10,000 sq ft | Max 5 ADUs | |
| Per-lot cap, lot > 10,000 sq ft | Max 6 ADUs | |
| Bonus ADUs | One bonus ADU per deed-restricted affordable ADU (very low / low / moderate income, 15 years); unlimited total only inside Transit Priority Areas; barred in certain low-income base zones (RS-1-1 through RS-1-11) unless the lot is in a High/Highest CTCAC Opportunity Area and residential in the community plan | |
| Bonus-unit requirements | Sprinklers mandatory on bonus units; 1 off-street space per affordable bonus ADU outside a TPA; High/Very High Fire Hazard Severity Zone lots must front a street with two evacuation routes | |
| Community Enhancement Fee | Applies to affordable + bonus floor area (Resolution R-316269) | |
| Bonus-agreement violations | Minimum penalty $10,000 per ADU per month | |
| ADU floor area | 150–1,200 sq ft | |
| Stories | Detached/attached limited to two stories in single-family zones | |
| Street side-yard setback | 4 ft, or the base-zone minimum, whichever is less | |
| Minimum rental term | 30 days (state minimum) | State floor; city-specific rental terms were also amended — confirm current terms. |
Ordinance O-21989: the 2025 rollback
Ordinance O-21989 — council vote June 16, 2025 (5–4), adopted July 22, 2025 — rolled back the city's 2020 near-unlimited bonus program. The caps and bonus rules in the table above are the rollback. Fee treatment also changed; confirm the current Development Impact Fee schedule (SDMC §142.0640(b)).
Standard plans: none of its own, three accepted sets
The city publishes no standard plans of its own. It accepts three outside sets: County of San Diego Standard ADU Plans (free, about 85% complete), Chula Vista City Standard ADU Plans, and Encinitas Permit-Ready ADU Plans.
Under AB 1332, applications using qualifying preapproved plans for detached ADUs get a 30-day review track (site-specific pieces still required). City program name: Companion Unit Program.
Separate sale (AB 1033): adopted
The city opted in via O-21989: ADUs are sellable separately through condo conversion since August 22, 2025. New and existing legally permitted ADUs qualify. Every lender must consent. Junior ADUs are excluded.
SDHC ADU Finance Program
The San Diego Housing Commission (SDHC) ADU Finance Program offers loans up to $250,000 plus free technical assistance: income at or below 80% of area median income, the unit rented affordably for 7 years, and no renting to family during the term. SDHC also publishes 4 ADU plan sets.
Demand and costs
City of San Diego ADU permits: 1,122 in 2025 (538 in 2024, 77 in 2023). Builder-guide construction range: $150,000–$400,000+.
Rent calculator
Defaults below are EXAMPLES — editable placeholders, not verified local rent or cost data. Type your own numbers.
Verified builders in San Diego County
One metro-level profile per builder, linked from every city page they serve. Profiles are never duplicated per city, so a correction lands everywhere at once.
Frequently asked questions
How many ADUs can I build on one lot in the City of San Diego?
It depends on lot size: at most 4 ADUs on lots up to 8,000 sq ft, 5 at 8,001–10,000 sq ft, and 6 above 10,000 sq ft. Bonus ADUs beyond that require a deed-restricted affordable ADU, and unlimited totals apply only inside Transit Priority Areas.
Do the new rules apply inside the coastal zone?
The 2025 rules (Ordinance O-21989) have applied outside the Coastal Overlay Zone since August 22, 2025. Inside the coastal zone, the older rules still apply until the Coastal Commission certifies the new rules (anticipated 2026).
Can I sell an ADU separately from the main house?
Yes, since August 22, 2025, via condo conversion — for new and existing legally permitted ADUs. Every lender must consent, and junior ADUs are excluded.
Does the city offer pre-approved ADU plans?
The city publishes none of its own. It accepts County of San Diego Standard ADU Plans (free), Chula Vista City Standard ADU Plans, and Encinitas Permit-Ready ADU Plans. Qualifying preapproved plans for detached ADUs get a 30-day review track under AB 1332.
Sources
- City of San Diego Ordinance O-21989 (council vote June 16, 2025; adopted July 22, 2025)
- SDMC §141.0302 (ADU regulations) and §142.0640(b) (fee schedule) — confirm current text
- Resolution R-316269 (Community Enhancement Fee)
- SDHC ADU Finance Program
- Builder guides — cost ranges
Not legal advice. This page is a starting point, not a parcel approval. Confirm your lot with the city before you build, buy, or sign anything.
Report an outdated rule
Rules change. If something on this page no longer matches the city's current rules, tell us what changed and where you saw it. Reporting is not wired to a destination yet — your note stays on this page and is not sent anywhere.