Santa Ana, in the heart of Orange County, offers strong rental demand driven by its central location. ADU construction is gaining momentum as homeowners seek to offset high housing costs.
Zoning & Size Requirements
| Allowed Zones | All residential zones (R1, R2, R3) |
| Max Size (Detached) | 1,200 sq ft |
| Max Size (Attached) | 1,200 sq ft or 50% of primary dwelling |
| Max Size (JADU) | 500 sq ft |
| Max Height | 25 ft |
| Max Units | 1 ADU + 1 JADU |
Setback Requirements
| Rear Setback | 4 ft |
| Side Setback | 4 ft |
| Front Setback | Per underlying zone |
| Parking Required | No parking required |
| Owner Occupancy | Not required |
| Min Lot Size | No minimum |
Permit Process & Fees
| Approval Process | Ministerial review |
| Review Timeline | 60 days |
| Permit Fees | $3,500-$12,000 |
| Impact Fees | Waived for units under 750 sq ft |
| Plan Check | Standard city review |
| Pre-Approved Plans | In development |
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Construction Costs
| Average Build Cost | $130,000-$300,000 |
| Cost per Sq Ft | $200-$360 |
| Garage Conversion | $75,000-$170,000 |
| Prefab ADU (Installed) | $100,000-$240,000 (installed) |
Finance Your ADU Project
Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders in minutes.
Compare ADU Financing Options →Rental Income Potential
| Avg Rent (1 Bedroom) | $1,700-$2,300/mo |
| Avg Rent (2 Bedroom) | $2,100-$2,900/mo |
| Short-Term Rental | Regulated; check city STR ordinance |
| Est. Annual ROI | 7-10% annual return |
Explore Prefab ADU Options
Prefab ADUs can save 20-40% vs. traditional construction and cut build time in half. Compare top prefab manufacturers.
Compare Prefab ADUs →Recent Law Changes
What's Changed Recently
- SB 1211 (Jan 2025): Multifamily expansion
- AB 1033 (2024): Separate sale provisions
- Orange County ADU builder market growing (2024-2025)
Tips for Building an ADU in Santa Ana
- Orange County rental demand makes Santa Ana ADUs very profitable
- Check fire zone requirements in hillside areas
- Consider dual-purpose ADUs that work for both long-term and family housing
- Connect with OC-focused ADU builders for better pricing
Frequently Asked Questions
Can I build an ADU in Santa Ana?
Yes. ADUs are allowed in All residential zones (R1, R2, R3) in Santa Ana. The maximum size for a detached ADU is 1,200 sq ft. No owner-occupancy is required.
How much does an ADU cost in Santa Ana?
ADU construction in Santa Ana typically costs $130,000-$300,000. Garage conversions run $75,000-$170,000, and prefab ADUs cost $100,000-$240,000 (installed).
How much can I rent an ADU for in Santa Ana?
Average ADU rents in Santa Ana are $1,700-$2,300/mo for a 1-bedroom and $2,100-$2,900/mo for a 2-bedroom unit.
Do I need parking for an ADU in Santa Ana?
No parking required. Check with Santa Ana planning department for the latest California ADU parking rules, as many states have relaxed requirements in recent years.
How long does it take to get an ADU permit in Santa Ana?
The permit review timeline in Santa Ana is 60 days. Fees range from $3,500-$12,000.
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