LotUpside is a one-stop ADU company for homes in the City of San Diego: we check your lot free against the city's rules, then match you with licensed designers and builders and coordinate the project with them.
Check your lot · free
What the San Diego rules allow on your lot: setbacks, the biggest unit that fits, fees.
Design your ADU · free
Shape it in live 3D: size, rooms, roof and finishes, with an estimate priced for San Diego.
Last verified 2026-10-15. Rules change; the City of San Diego Development Services Department has the final word.
An ADU 16 ft tall or less can go up to the side and rear lot lines unless the lot is in a High or Very High Fire Hazard Severity Zone, where it keeps 4 ft. A taller ADU next to a residential lot keeps 4 ft (or the zone's smaller setback), and building and fire codes can still require more distance from a lot line.
San Diego Municipal Code 141.0302(b)(9)(C) and (D)San Diego waives its Development Impact Fees on the first two ADUs on a lot, whatever their size, unless they are over 750 sq ft and built with a Senate Bill 9 two-home project. School fees still apply to ADUs and junior ADUs at the school district's rate, and so do the City's building permit fees.
San Diego Municipal Code 142.0640(b)(1)(A); City Information Bulletin 400 (Fees)In the Coastal Overlay Zone, an ADU needs a Coastal Development Permit unless it is carved out of the house's existing living space. In the zone's non-appealable area the City can issue it with the building permit, and several recent City ADU amendments don't apply in the zone until the Coastal Commission approves them.
City of San Diego Information Bulletin 400 (Coastal Development Permit Requirement)If the City's Seismic Safety Study maps put the lot in one of the fault, landslide, liquefaction or coastal bluff categories Table 145.1803(1) lists for homes, a new ADU needs a geotechnical report before the building permit; the Building Official may waive it in some cases. The City's own fire hazard map, in effect since Aug. 30, 2025, adds areas the State's map doesn't rate Very High, and an ADU in a High or Very High zone keeps 4 ft from side and rear lot lines.
San Diego Municipal Code 145.1803 and Table 145.1803(1); City of San Diego Fire Hazard Severity Zone Map (O-21992)The City accepts the County of San Diego's and Chula Vista's standard ADU plans and Encinitas' permit-ready ADU plans, and permit applications that use them get a 30-day review. You license a plan from its provider, and it still has to meet San Diego's development rules and current building codes.
City of San Diego Development Services, ADU/JADU page (Preapproved ADU Plans)| Type | Est. all-in cost | Est. rent |
|---|---|---|
| Garage conversion | $232-$377 per sq ft of garage (about $93,000-$151,000 for a 400 sq ft garage) | $1,750-$2,525/mo |
| Junior ADU (inside the house) | $85,000-$160,000 | $1,500-$1,900/mo |
| Detached studio | $206,000-$303,000 | $1,750-$2,250/mo |
| Detached 1 bedroom | $281,000-$413,000 | $2,150-$2,750/mo |
| Detached 2 bedroom | $255,000-$460,000 | $2,500-$3,350/mo |
| Detached 3 bedroom | $295,000-$484,000 | $3,175-$4,025/mo |
Estimates for a first conversation, not bids or appraisals. Source: LotUpside price book sd-2026-10. Provisional estimate: rent, build-cost and value figures come from San Diego price lists and City fee schedules and have not yet been checked against a local builder's quote. They are not quotes, bids or appraisals.
Free lot check
A 12-check property screening from public records: what fits on your lot and what it adds.
Get matched with a licensed designer
Ask for a free consult and we look for a licensed designer for your plans and permit.
Get matched with a licensed builder
The builder holds the construction contract; we coordinate the project with them.
Licensed partners design and build, and the builder holds the construction contract. Partners are signed in some areas so far. All figures are estimates, not bids.
Rules from City of San Diego ADU ordinance (SDMC 141.0302) and City of San Diego Information Bulletin 400; zoning from the City of San Diego Official Zoning Map, CA Gov. Code 66314. Plus county parcel and assessor maps, CAL FIRE fire zones, FEMA flood maps, the California Geological Survey, the USDA soil survey, USGS elevation and Microsoft building outlines.
San Diego rents and build costs are provisional: price lists and City fee schedules, not yet checked against a local builder's quote. Coastal, planned-district and overlay lots stop at 'needs a closer look'.
Measured ADU layouts you can edit and download as CAD files, then check against the San Diego rules above.
We'll match you with a licensed designer and builder in your area and coordinate the project. Free consult, no obligation.
We'll match you with a licensed designer and builder in your area and coordinate the project. Free consult, no obligation.
Licensed partner designers and builders do the design and construction, and the builder holds the construction contract. Partners are signed in some areas so far; elsewhere we'll tell you plainly what we can do.
As tall as the lot's base and overlay zones allow, and no more than two stories on lots zoned for a single home, under San Diego Municipal Code 141.0302(b)(8). State law (Government Code 66321(b)(4)) requires the City to allow at least 16 ft for a detached ADU, or 18 ft within a half-mile walk of major transit.
Yes, outside the Coastal Overlay Zone conditions (in that zone the structure must also meet the coastal rules of 141.0302(a)(7) and needs a Coastal Development Permit). An ADU built inside an existing garage or other accessory structure keeps that structure's setbacks, has no size cap and may add up to 150 sq ft for getting in and out, under San Diego Municipal Code 141.0302(a)(5) and (b)(7)(D). The lost parking doesn't need replacing unless the lot is in the Beach Impact Area outside a transit priority area (141.0302(b)(10)(C)).
Not an ADU: San Diego Municipal Code 141.0302(a)(8) bars rental terms shorter than 31 consecutive days. The code sets no term for a junior ADU, but the City's ADU page and Information Bulletin 400 apply the same rule to junior units, so plan on rentals of a month or longer.
Yes. San Diego lets owners turn a new or existing ADU into a condominium and sell it separately, following the subdivision steps in San Diego Municipal Code 141.0302(f). ADUs built through the City's ADU Home Density Bonus program can't be sold separately, according to the City's ADU page, and a junior ADU never can (141.0302(c)(1)(D)).
The free check gives the verdict from a 12-check property screening, your best move with the value it adds, the monthly rent and the cash you put in. The full report adds every option ranked, cost vs value ranges, concept floor layouts and site plan drafts, and every check with its sources. It is a one-time payment per property.
Neither. It is a screening from public records, not professional advice, and not a survey, soils report, appraisal, loan offer or permit; every number is an estimate. A licensed designer confirms the final plan, and your city or county gives final approval.