Phoenix allows ADUs in residential zones with reasonable size limits and setback requirements. The city's rapid growth has prompted more liberal ADU policies, though regulations remain somewhat conservative compared to western coastal cities.
Zoning & Size Requirements
| Allowed Zones | Single-family residential zones |
| Max Size (Detached) | 900 sq ft |
| Max Size (Attached) | 800 sq ft |
| Max Size (JADU) | Not allowed |
| Max Height | 35 feet |
| Max Units | 1 ADU per lot |
Setback Requirements
| Rear Setback | 15 feet |
| Side Setback | 5 feet |
| Front Setback | 25 feet |
| Parking Required | 1 space per unit |
| Owner Occupancy | Not required |
| Min Lot Size | 5,000 sq ft |
Permit Process & Fees
| Approval Process | Building permit |
| Review Timeline | 60-90 days |
| Permit Fees | $2,500-$4,200 |
| Impact Fees | $900-$1,600 |
| Plan Check | 2-3 weeks |
| Pre-Approved Plans | Limited availability |
Get Free ADU Quotes in Phoenix
Connect with pre-vetted ADU contractors in your area. Free, no obligation.
🔒 Your info is secure. We connect you with up to 3 vetted local contractors. No spam, no obligation.
Construction Costs
| Average Build Cost | $120,000-$240,000 |
| Cost per Sq Ft | $135-$270 |
| Garage Conversion | $60,000-$140,000 |
| Prefab ADU (Installed) | $85,000-$200,000 (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) | $1,250-$1,700/mo |
| Avg Rent (2 Bedroom) | $1,600-$2,200/mo |
| Short-Term Rental | Varies by neighborhood |
| 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
- 2024: Streamlined ADU permitting process
- 2023: Increased max detached ADU size from 800 to 900 sq ft
- 2024: Expanded ADU allowance in infill zones
- 2023: Reduced setback requirements for corner lots
Tips for Building an ADU in Phoenix
- Phoenix's rapid growth supports strong appreciation potential
- Heat considerations; ensure adequate cooling systems for ADU
- Water availability and HOA restrictions common; verify early
- Strong rental demand due to ongoing population growth
Frequently Asked Questions
Can I build an ADU in Phoenix?
Yes. ADUs are allowed in Single-family residential zones in Phoenix. The maximum size for a detached ADU is 900 sq ft. No owner-occupancy is required.
How much does an ADU cost in Phoenix?
ADU construction in Phoenix typically costs $120,000-$240,000. Garage conversions run $60,000-$140,000, and prefab ADUs cost $85,000-$200,000 (installed).
How much can I rent an ADU for in Phoenix?
Average ADU rents in Phoenix are $1,250-$1,700/mo for a 1-bedroom and $1,600-$2,200/mo for a 2-bedroom unit.
Do I need parking for an ADU in Phoenix?
1 space per unit. Check with Phoenix planning department for the latest Arizona ADU parking rules, as many states have relaxed requirements in recent years.
How long does it take to get an ADU permit in Phoenix?
The permit review timeline in Phoenix is 60-90 days. Fees range from $2,500-$4,200.
Ready to Build in Phoenix?
Get free, no-obligation quotes from top-rated ADU contractors in Phoenix.
Get Free Quotes →