Arizona ADU Rules Law: Statewide Accessory Structures Rules (2026)

Key Facts

Statute: ARS 9-461.18
Bill: SB-1161 (2024)
Applies To: Cities over 75,000
Max Size: 1,000 sq ft or 75%

Full Breakdown

Codified at ARS 9-461.18, SB-1161 forces qualifying cities to allow at least one attached and one detached ADU on any lot zoned for single-family use. Cities cannot require owner occupancy, mandate more than one parking space per ADU, impose lot sizes greater than the principal-dwelling minimum, or charge unrelated impact fees. ADUs up to 1,000 square feet or 75% of the primary dwelling (whichever is less) must be allowed by-right. Restrictions on short-term rental of ADUs are permitted, but blanket bans on long-term rental are not.

Violations & Penalties

Municipal denials inconsistent with SB-1161 are subject to civil action and reversal. Property owners may seek declaratory relief and attorney's fees if a city violates the statute.

Frequently Asked Questions

Do all Arizona cities have to allow ADUs under SB-1161?

No. The state preemption applies only to municipalities with populations of 75,000 or more. Smaller towns and counties retain full discretion over ADU zoning.

Can my city require owner occupancy for an ADU?

No. Under ARS 9-461.18, cities subject to SB-1161 cannot impose owner-occupancy requirements on either the primary dwelling or the accessory dwelling unit.

Arizona ADU Preemption Law SB-1161 Explained

Key Facts

Full Breakdown

Violations & Penalties

Frequently Asked Questions

Sources

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