ADU Permits: Peoria vs Phoenix
How do adu permits rules compare between Peoria, AZ and Phoenix, AZ?
Peoria has fewer restrictions than Phoenix.
Peoria, AZ
Maricopa County
Peoria permits accessory dwelling units (often locally called casitas) by-right under Arizona Revised Statutes section 9-461.18, enacted by HB 2720 in 2024 and effective for cities over 75,000 population on or before January 1, 2025. Peoria (population approximately 190,000) is subject to the mandate. The Peoria Zoning Ordinance (PZO) Article 14-2 (Residential Districts) was amended to comply. Single-family lots may have one detached and one attached ADU; lots over one acre may add a third detached unit.
View full Peoria rules →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 →Key Facts Comparison
| Fact | Peoria | Phoenix |
|---|---|---|
| State Mandate | Ariz. Rev. Stat. 9-461.18 (HB 2720) | - |
| City Reference | Peoria Zoning Ordinance Article 14-2 | - |
| Units Allowed | 1 detached + 1 attached (3 if 1+ acre) | - |
| Maximum Size | 75% of primary or 1,000 sq ft | - |
| Permit Authority | Peoria Development and Engineering | - |
| By-Right Standard | Yes on single-family lots | - |
| 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 |
Highlighted rows indicate differences between cities.
Peoria FAQ
Can I build a casita ADU in Peoria by-right?
Yes. Under Arizona HB 2720 (Ariz. Rev. Stat. 9-461.18), Peoria must allow one detached and one attached ADU by-right on every single-family lot. Lots over one acre may add a third detached unit. Building, plumbing, electrical, and fuel-gas permits through Peoria Development and Engineering are still required.
How big can my Peoria ADU be?
Under ARS 9-461.18, your ADU may not exceed 75% of the gross floor area of the primary dwelling or 1,000 square feet, whichever is less. Setback, height, and lot-coverage standards from Peoria's residential zoning district still apply to the structure itself.
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.
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