ADU Cost in San Diego (2026 Complete Breakdown by Type)
Vision ADU San Diego ·
2026 ADU pricing in San Diego County
San Diego ADU costs in 2026 typically run $215k–$420k all-in depending on type, size, and city. Here are real ranges from completed projects.
By ADU type
| Type | Size | All-in Cost |
|---|---|---|
| Garage Conversion | 300–500 sf | $130k–$220k |
| JADU | up to 500 sf | $115k–$210k |
| Attached ADU | 500–1,200 sf | $195k–$360k |
| Detached Studio | 350–500 sf | $185k–$290k |
| Detached 1-BR | 500–750 sf | $215k–$345k |
| Detached 2-BR | 750–1,200 sf | $270k–$420k |
By San Diego County city
| City | Per-sf (detached) | Permit fees |
|---|---|---|
| City of San Diego | $310–$390 | $9k–$15k |
| Chula Vista | $290–$370 | $7k–$12k |
| Oceanside | $300–$380 | $8k–$13k |
| Escondido | $285–$365 | $7k–$11k |
| Carlsbad | $340–$430 | $10k–$17k |
| La Mesa | $295–$380 | $7k–$12k |
What is included in our all-in estimates
Architectural design, structural engineering, Title 24 energy, permits and plan check, foundation, framing, plumbing, electrical, HVAC, drywall, paint, cabinets, flooring, appliances, doors/windows, solar PV (state law), utility connections, and final inspections.
What is NOT included by default
- Major grading or retaining walls (hillside lots)
- Sewer capacity fees beyond standard
- HOA reviews or fees
- Property landscape restoration beyond ADU footprint
- Furniture, appliances beyond standard
SD financing options
- HELOC: prime + 0–1%
- Cash-out refi: 6.5–7.5% in 2026
- Renofi loan: future-value based
- Construction-to-perm: 7.5–9%
Get an exact quote for your SD lot
Book a free site evaluation and we deliver a written, itemized estimate within 72 hours.
Frequently Asked Questions
What is the average ADU cost in San Diego County in 2026? $235k–$370k all-in for typical detached new construction.
Is San Diego cheaper than LA for ADUs? Slightly — typically 5–10% lower per square foot due to lower permit fees in many SD cities.
How much does a 1,200 sq ft ADU cost in San Diego? $320k–$500k all-in depending on city and finishes.
Are there discounts for pre-approved plans? Yes — using City of San Diego pre-approved plans can save $8k–$18k in design and permit time.
What is the cheapest type of ADU in San Diego? Garage conversions starting at $130k for simple conversions.