ADU Permits: Phoenix vs Surprise
How do adu permits rules compare between Phoenix, AZ and Surprise, AZ?
Surprise has fewer restrictions than Phoenix.
Phoenix, AZ
Maricopa County
Phoenix processes ADU permits through Planning and Development under PZC Section 608 (Casita Ordinance) and 2024 Phoenix ADU updates. Arizona HB 2928 (effective 2025) preempts local restrictions in cities over 75,000 residents, requiring ministerial approval for ADUs meeting state standards.
View full Phoenix rules →Surprise, AZ
Maricopa County
Surprise must allow accessory dwelling units (ADUs) by right in single-family residential zones under Arizona HB 2720 (2024), codified at ARS § 9-461.18. With a population near 143,000 the city exceeds the 75,000 threshold and is preempted from prohibiting one attached and one detached ADU per single-family lot. The Surprise Zoning Ordinance Section 106-10.2 (ADUs) within Chapter 106 (Zoning and Use Standards) implements the state mandate, and building permits issue through the Community Development Department.
View full Surprise rules →Key Facts Comparison
| Fact | Phoenix | Surprise |
|---|---|---|
| State Law | AZ HB 2928 (2025) | - |
| City Code | Phoenix PZC Section 608 | - |
| Max Size | 75% primary or 1,000 sq ft | - |
| Review Type | Ministerial (no hearing) | - |
| Review Time | 10-20 business days | - |
| Code Section | - | Surprise Zoning § 106-10.2 |
| State Mandate | - | ARS § 9-461.18 (HB 2720) |
| Population Trigger | - | Surprise > 75k (by-right) |
| Permitted Zones | - | RR, R-1, R-2, R-3 (by right) |
| Min Detached Size | - | 1,000 sq ft (state floor) |
Highlighted rows indicate differences between cities.
Phoenix FAQ
Do I need a permit for a Phoenix ADU?
Yes. All ADUs require building permits through Phoenix Planning and Development under PZC Section 608. Under HB 2928, review is ministerial (over-the-counter) without public hearings, but full structural and trade permits are required.
How big can my Phoenix ADU be?
Under Arizona HB 2928, ADUs are limited to 75 percent of the primary dwelling size or 1,000 square feet, whichever is less. Phoenix cannot impose a smaller maximum size than state law.
Surprise FAQ
Can I build an ADU in Surprise by right?
Yes. Arizona HB 2720 (ARS § 9-461.18) requires Surprise to permit one attached and one detached ADU per single-family lot by right because the city exceeds 75,000 population. File for a building permit with Surprise Community Development under Zoning § 106-10.2.
Does the Sun City Grand HOA affect my ADU rights?
Yes. ARS § 9-461.18 binds the city but does not override private HOA covenants. Sun City Grand (The Grand), Sun Village, and similar age-restricted communities can restrict or prohibit ADUs through CC&Rs. Read your HOA documents before applying.
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