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 [1][2]
| Allowed Zones | Single-family residential zones |
| Max Size (Detached) | 900 sq ft |
| Max Size (Attached) | 75% of primary dwelling, capped at 1,000 sq ft (lots ≤10,000 sq ft) |
| Max Size (JADU) | Not allowed |
| Max Height | 15 ft (use permit may allow more) |
| Max Units | 1 ADU per lot |
Setback Requirements [1][2]
| Rear Setback | 15 feet |
| Side Setback | 5 feet |
| Front Setback | 25 feet |
| Parking Required | No additional parking required (AZ HB 2720, effective Jan 2025) |
| Owner Occupancy | Not required |
| Min Lot Size | 5,000 sq ft |
Permit Process & Fees [3]
| 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 |
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Construction Costs [4][5]
| 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 |
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Rental Income Potential [6][7]
| 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 |
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Recent Law Changes
What's Changed Recently
- Phoenix expanded ADU-allowed zones to cover all single-family residential (2026)
- Scottsdale updated ADU design standards with modern architectural options
- Tucson ADU incentive program: Waived permits for units under 500 sq ft
- Arizona SB 1117 effects: State preemption of local ADU restrictions expanding
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
Sources & References
All data on this page is sourced from official government records and verified market data. View our full methodology.
- Accessory Dwelling Units (ADU) | City of Phoenix Planning Department — Accessed 2026-02-24
- Phoenix Zoning Ordinance Section 706 — ADU Standards Municipal Code — Accessed 2026-02-25
- ADU Beginner's Guide | City of Phoenix (PDF) Planning Department — Accessed 2026-02-24
- HomeAdvisor — ADU Construction Cost Data Market Data — Accessed 2026-02-24
- Angi — Local ADU Contractor Costs Market Data — Accessed 2026-02-24
- Zillow Rental Manager — Market Rent Data Market Data — Accessed 2026-02-24
- HUD Fair Market Rents Government Data — Accessed 2026-02-24
- Phoenix Zoning Ordinance — ADU Amendment Z-TA-2-24 Municipal Code — Accessed 2026-02-24
- Arizona ADU Legislation (SB 1132, 2023) Government Data — Accessed 2026-02-24
Frequently Asked Questions
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