ADU Permits: Glendale vs Phoenix
How do adu permits rules compare between Glendale, AZ and Phoenix, AZ?
Glendale has fewer restrictions than Phoenix.
Glendale, AZ
Maricopa County
Glendale permits accessory dwelling units 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. Glendale (population approximately 250,000) is subject to the mandate. Glendale City Council adopted ADU amendments to the Uniform Development Code (Chapter 35) on December 10, 2024. Single-family lots may have one detached and one attached ADU; lots over one acre may add a third.
View full Glendale 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 | Glendale | Phoenix |
|---|---|---|
| State Mandate | Ariz. Rev. Stat. 9-461.18 (HB 2720) | - |
| City Ordinance Adopted | Dec 10, 2024 (Ch. 35 UDC) | - |
| Units Allowed | 1 detached + 1 attached (3 if 1+ acre) | - |
| Maximum Size | 75% of primary or 1,000 sq ft | - |
| Separate Water Meter | Required (Glendale rule) | - |
| Building Code | 2024 IRC / IFGC as adopted | - |
| 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.
Glendale FAQ
Can I build an ADU in Glendale by-right?
Yes. Under Arizona HB 2720 (Ariz. Rev. Stat. 9-461.18) and Glendale's December 10, 2024 amendments to the Uniform Development Code (Chapter 35), Glendale 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 Glendale Building Safety are still required.
Does my Glendale ADU need a separate water meter?
Yes. Glendale requires all accessory dwelling units to have separate utility meters including a separate city water meter, which requires a new water tap to the city water main in the street or right-of-way. The ADU shares the primary address with a Unit 1 and Unit 2 suffix rather than receiving a new address.
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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