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.
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.
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.
Where is your property?
California ADU costs and rents vary a lot by market. Use your city or a ZIP.
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.
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