ADU Permits: Mesa vs Surprise
How do adu permits rules compare between Mesa, AZ and Surprise, AZ?
Mesa and Surprise have similar restriction levels.
Mesa, AZ
Maricopa County
Mesa permits ADUs by right in all single-residence districts under Mesa Zoning Ordinance Title 11, Section 11-31-3, as updated by Ordinances 5883 and 5950 to comply with Arizona HB 2720. Internal, attached, and detached ADUs are allowed. Maximum 75% of the primary residence interior habitable area or 1,000 sq ft, whichever is less. No minimum lot size and no additional parking required.
View full Mesa 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 | Mesa | Surprise |
|---|---|---|
| State Law | AZ HB 2720 (effective 2025) | - |
| City Code | MZO §11-31-3 (Ord. 5883) | - |
| Max Size | 75% primary or 1,000 sq ft | - |
| Min Lot Size | None | - |
| Parking | Not required | - |
| ADUs Per Lot | 1 attached + 1 detached by right | - |
| 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.
Mesa FAQ
Do I need a permit for a Mesa ADU?
Yes. All ADUs require building permits through Mesa Development Services. Under HB 2720 and MZO Section 11-31-3, review is ministerial (over-the-counter) without public hearings. Full structural, electrical, mechanical, and plumbing trade permits are required.
How many ADUs can I build on my Mesa lot?
At least one attached and one detached ADU are permitted by right on any lot where a single-family dwelling is permitted, with no minimum lot size. On lots of at least one acre, a third ADU (second detached) is permitted only if deed-restricted as affordable to households at 80% AMI.
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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