ADU Cost in San Diego
San Diego ADUs typically cost $280K–$410K to build and rent for $2,400–$3,400/month — the ADU Bonus Program allows multiple ADUs on some lots.
A detached 850 sq ft ADU in San Diego typically costs between $280,000 and $410,000 and rents for $2,400 to $3,400 per month in 2026. San Diego is widely considered one of California's most builder-friendly ADU markets, primarily because of the city's ADU Bonus Program — a locally-created overlay that allows qualifying lots to build multiple ADUs (up to 4-6 on some single-family parcels) in exchange for affordability commitments on a subset. For standard single-ADU projects, San Diego's ministerial review and streamlined permit process make timelines predictable, and build costs are lower than Los Angeles.
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Mid-range 850 sq ft detached ADU in San Diego.
Typical San Diego ADU rent at this size/finish.
Years to pay back construction from rent, net of operating cost.
San Diego's ADU bonus program allows multiple ADUs on some lots — one of the most builder-friendly policies in the state.
Maintained by the AduCalc editorial team. These directional ranges combine the AduCalc city cost multiplier, 2024–2026 California ADU project data, HCD ADU guidance, RentCafe California rent benchmarks, local MLS comps, and contractor bid inputs. Verify final feasibility, fees, and permit timing with the local planning department before committing to plans.
How does San Diego ADU permitting work?
San Diego's Development Services Department runs ministerial ADU review within state-mandated 60-day timelines. Standard single-ADU permits typically issue 3-4 months from complete submittal. The ADU Bonus Program adds a separate application pathway for multi-ADU projects with affordability agreements — those can take 4-8 months but unlock density that's unavailable elsewhere in California. Coastal Zone lots (beach-adjacent neighborhoods) require a coastal development permit or exemption, adding 4-8 weeks. Historic-district lots in Hillcrest, North Park, South Park, and Golden Hill require compatibility review. Setbacks follow state minimums.
What drives ADU cost in San Diego?
San Diego ADU costs run 5-15% below LA averages, primarily because of lower labor rates and a deep bench of small-to-mid residential contractors competing for ADU work. Title 24, solar mandate, and San Diego's specific water-efficiency requirements apply. Coastal-adjacent lots (La Jolla, Pacific Beach, Ocean Beach, Mission Beach) face corrosion and salt-air considerations — stainless fasteners, marine-grade finishes, upgraded exterior materials — typically $5K-$15K incremental cost. Hillside and canyon-adjacent lots (Mission Valley, Scripps Ranch, parts of La Jolla) add grading and retaining work. Mid-range 850 sq ft detached ADU bids on flat inland lots typically land at $310K-$370K.
ADU cost by type in San Diego.
| ADU type | Typical size | Cost range | Monthly rent |
|---|---|---|---|
| Detached ADU | 600–1200 sq ft | $305K–$406K | $2,450–$2,950 |
| Garage Conversion | 300–600 sq ft | $101K–$135K | $1,250–$1,500 |
| Attached ADU | 500–1000 sq ft | $232K–$309K | $2,000–$2,400 |
| Junior ADU (JADU) | 300–500 sq ft | $106K–$142K | $1,100–$1,350 |
What rent can a San Diego ADU command?
San Diego ADU demand is strong and diverse. UCSD, SDSU, and University of San Diego produce university-driven demand. Naval Base San Diego, Naval Station Coronado, and MCAS Miramar anchor a military tenant base. Qualcomm, Scripps Health, UCSD Health, and the booming biotech corridor in Sorrento Valley and Torrey Pines produce professional demand. A new 1BR detached ADU in North Park, University Heights, Clairemont, or Kearny Mesa leases for $2,600-$3,100 per month; 2BR units run $2,800-$3,400. Coastal neighborhoods (Pacific Beach, Ocean Beach, La Jolla) command $300-$700 premiums. Vacancy on quality ADUs is typically under 4%.
What fits on a San Diego lot?
San Diego's median single-family lot is about 7,200 sq ft — among the larger averages for California coastal metros. Postwar neighborhoods (Clairemont, Kearny Mesa, Rancho Bernardo, Scripps Ranch) feature rectangular lots 60-80 feet wide and 120-150 feet deep, comfortably fitting 1,000-1,200 sq ft detached ADUs. Older neighborhoods (North Park, Normal Heights, Kensington) have tighter lots with more density considerations. The ADU Bonus Program particularly rewards owners of larger lots (8,000+ sq ft) who want to maximize density.
Who is a San Diego ADU best for?
San Diego is California's most flexible ADU market for owners with ambition. Standard single-ADU projects produce strong payback windows (10-13 years typical) with moderate build costs and strong rent. The ADU Bonus Program unlocks genuinely unusual density — a qualifying 10,000 sq ft lot can potentially host 4-6 ADUs in exchange for making one or two of them deed-restricted affordable. This is a sophisticated path that works for investors and owners with capital and longer timelines, but the long-term yield math can dramatically outperform single-ADU approaches. For simpler strategies, a 2BR detached ADU in Clairemont, Kearny Mesa, or University Heights offers clean economics.
- ADU Bonus Program allows multiple ADUs on qualifying lots in exchange for affordability commitments.
- Coastal Zone lots need a coastal development permit and corrosion-resistant construction.
- Biotech corridor and university employment drives consistent professional tenant demand.
Run the numbers for your San Diego lot.
The calculator is pre-filled for San Diego. Switch the ADU type, size, or finish to see how each changes the numbers.
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Other CA ADU markets near San Diego.
San Diego ADU frequently asked questions.
The ADU Bonus Program is a San Diego-specific overlay that allows qualifying single-family lots to build additional ADUs (up to 4-6 total on some lots) in exchange for making a subset deed-restricted affordable for a specified period. It's one of California's most generous local ADU density programs.
Model your San Diego ADU potential today.
A 2-minute calculator tuned for San Diego market data. Transparent, California-specific, no contractor spam.
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