ADU Bonus Program Changes
1. Unit Caps in Single-Family Zones (RS) in SDAs
Change: ADUs/JADUs on single-family lots in Sustainable Development Areas (SDAs) are now capped:
- ≤ 6 units for ≥10,001 ft² lots
- 5 units for 8,001–10,000 ft²
- 4 units for ≤ 8,000 ft²
Affected: RS-1-1 to RS-1-4 and RS-1-8 to RS-1-11 zones in SDAs.
Unaffected: RS-1-5 to RS-1-7, Multifamily zones (RM/RM/C zones) and Transit Priority Area (TPA) exemptions.
Challenge: Limits speculative backyard apartment farms on larger lots.
Opportunity: Leads to better-scaled, neighborhood-integrated projects. Restrictions do not apply in High and Highest CTCAC Opportunity Zones leading developers to not only invest in underserved and lower income neighborhoods, but also receive tax credit to do so.
2. Fire Safety & Evacuation Requirements
Change: In high fire zones, bonus ADU projects must have two exit routes, sprinklers, and stricter setbacks; cul-de-sac/inaccessible RS lots excluded.
Challenge: Adds complexity and potentially reduces buildable area.
Opportunity: Creates safer, more resilient housing—enhances project credibility and insurance ease. And let’s face it, San Diego has had devastating fires in the past like the ones that ripped through and destroyed LA 6 months ago. Would you really build an investment property and not protect it with a sprinkler system for a few thousand more?
3. Off-Street Parking Mandate
Change: One parking space required per bonus/affordable ADU outside TPAs. No parking mandated inside TPAs.
Challenge: Reduces yield or increases project costs for non–TPA developments.
Opportunity: Better street management, neighborhood acceptance, and lowers tenant turnover. Developers who do not provide at least one parking space per unit are feeling the weight of regret over that decision.
4. Development Scale & Floor Area Ratio (FAR) Cap
Change: Projects capped at FAR equivalent to an 8,000 ft² lot; excludes steep and sensitive areas.
Challenge: Restricts overly large bonus ADU footprints.
Opportunity: Promotes thoughtful design, reduces environmental impact, and improves neighborhood fit.
5. Community Enhancement Fee
Change: ADUs under 750 ft² must pay a new fee supporting local infrastructure & parks.
Challenge: Adds cost to smaller, cheaper units.
Opportunity: Funds improvements that improve overall livability—strengthening community buy-in.
6. Deed Restriction & Affordable Unit Requirements
Change: Affordable/bonus ADUs must match size/bedroom count of bonus units; deed restrictions due before the first permit; penalties up to $10k/month for violations.
Challenge: Increases administrative burden.
Opportunity: Ensures quality, stability in long-term affordable rentals—enhancing social impact and investment appeal.
Who Is Affected vs. Who Isn’t
| Zone Type | Caps & Rules Apply? |
|---|---|
| Single-family (RS) in SDA | Yes |
| RS zones outside SDA | Limited bonus only |
| Multifamily zones (RM, etc.) | Unaffected |
| Transit Priority Areas | Parking waiver applies |
Final Takeaways
Challenge: Single-family zones face tighter controls—unit limits, fees, and design constraints.
Opportunity: Projects become safer, better integrated, and more community-friendly.
For multifamily lots, the program remains robust—with full bonus potential and no new caps. Combine ADUs or jump straight into Complete Communities Housing Solutions (CCHS) for even greater density and flexibility while delivering high-quality, long-term housing.
This page is provided for general informational purposes only and is intended as a high-level overview of recent changes to the City of San Diego’s ADU Bonus Program. Program requirements, fee structures, eligibility criteria, and interpretations are subject to change and may vary based on zoning, site conditions, overlay zones, fire regulations, and agency discretion. This content does not constitute legal, financial, or entitlement advice. Project feasibility, unit yield, and affordability obligations must be evaluated on a site-specific basis in coordination with the appropriate public agencies and professional consultants.