ADU Permits: Surprise vs Tempe
How do adu permits rules compare between Surprise, AZ and Tempe, AZ?
Surprise and Tempe have similar restriction levels.
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 →Tempe, AZ
Maricopa County
Tempe permits accessory dwelling units by right on lots zoned for single-family use under Arizona Revised Statutes section 9-461.18, enacted by HB 2720 in 2024. Tempe (population approximately 185,000) is well over the 75,000 threshold that triggers the state by-right mandate. Tempe's Zoning and Development Code was amended to comply, allowing at least one attached and one detached ADU per single-family lot. Building permits issue through Tempe Community Development.
View full Tempe rules →Key Facts Comparison
| Fact | Surprise | Tempe |
|---|---|---|
| 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) | - |
| State Law | - | ARS 9-461.18 (HB 2720) |
| City Code | - | Tempe ZDC + City Code Ch. 8 |
| Units Allowed | - | 1 attached + 1 detached by right |
| Max Side/Rear Setback | - | 5 ft (state cap) |
| Population Threshold | - | Tempe ~185k qualifies (over 75k) |
| Review | - | Tempe Community Development |
Highlighted rows indicate differences between cities.
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.
Tempe FAQ
Can I build a casita in Tempe by right?
Yes. Under Arizona HB 2720 (ARS 9-461.18), Tempe must allow one attached and one detached ADU by right on any single-family lot. Discretionary use permits and public hearings are preempted. You still need building, electrical, plumbing, and mechanical permits through Tempe Community Development.
How close to my property line can the ADU sit in Tempe?
The state statute caps the side and rear yard setbacks Tempe can impose at no more than 5 feet. Tempe's Zoning and Development Code was updated to comply. Front yard setbacks follow the underlying single-family district standards.
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