As of October 2026, average apartment rents in the City of San Diego run about $2,055 to $2,241 a month for a studio and about $2,439 to $2,722 for a one-bedroom, depending on the data source. A well-built ADU can compete in that range. Size, neighborhood, privacy and what you include set the actual rent.
What do San Diego rentals go for right now?
| Unit size | City of San Diego, RentCafe (data as of September 30, 2026) | City of San Diego, Apartments.com (October 2026) | San Diego County, RentCafe (September 30, 2026) |
|---|---|---|---|
| Studio | $2,241 | $2,055 | $2,191 |
| One bedroom | $2,722 | $2,439 | $2,495 |
| Two bedrooms | $3,351 | $3,070 | $3,024 |
These are averages for apartments, not ADUs specifically, and they blend new and old buildings. Use them as a reference point, then compare against listings near your address.
What moves an ADU's rent up or down?
- Location. Coastal and central neighborhoods generally rent higher than inland ones.
- Bedrooms and layout. A true one-bedroom usually beats a studio of similar size.
- Privacy. A separate entry, its own outdoor space and distance from the main house matter to tenants.
- Inclusions. In-unit laundry, a parking spot, air conditioning and utilities.
- Finish quality. New construction can command more than an older apartment of the same size.
What rental rules apply in San Diego?
- No short-term rentals in newer ADUs. As reported by KPBS in September 2025, ADUs permitted in the city after September 2017 cannot be rented short-term.
- Junior ADUs. As of October 2026, state law requires rentals longer than 30 days.
- Bonus ADU units. Units built under the Bonus ADU program include deed-restricted affordable ADUs for 15 years, which limits what those units can charge.
- No owner-occupancy rule for ADUs under state law, so you can rent both the ADU and the main home.
Will an ADU raise my property taxes?
Some. Under California's Proposition 13 rules, as explained by the Howard Jarvis Taxpayers Association, only the new square footage is assessed at market value when construction is finished; the rest of your property keeps its existing assessment. The San Diego County Assessor's office can tell you how it would treat your plans.
How do I sanity-check the numbers?
Start with gross rent: a unit renting at $2,500 a month brings in $30,000 a year before costs. Subtract property tax on the added value, insurance, maintenance, any utilities you cover and vacancy. Compare what remains to the project cost and any financing. Those numbers are an illustration, not a projection for your lot.
Sources, as of October 2026:
- RentCafe, San Diego, CA and San Diego County rental market trends (data as of September 30, 2026).
- Apartments.com, San Diego, CA rent market trends (updated October 18, 2026).
- KPBS, "How new San Diego homes intended for residents became vacation rentals" (September 18, 2025).
- Howard Jarvis Taxpayers Association, "Will my property taxes go up if I build a granny flat in the backyard?"
- City of San Diego Planning Department, Housing Toolkit: Accessory Dwelling Units page, sandiego.gov.
- California Department of Housing and Community Development (HCD), ADU Handbook, updated March 2026, with its addendum on law in effect January 1, 2026, hcd.ca.gov.