ADU Laws in Arizona (2026)
Arizona state ADU law details, key provisions, preemption status, and recent legislative changes for accessory dwelling units.
Law Name
Arizona House Bill 2720 (HB 2720) — Accessory Dwelling Units; Requirements · Verified June 25, 2026 · Source
Effective Date
2024-09-14
Preempts Local Ordinances
Yes — state law overrides local restrictions
Has State Law
Yes
Statewide ADU Preemption Applies
State law establishes statewide preemption standards that supersede local regulations. The citation and source below confirm the verified legal basis.
Key Provisions
Removes owner-occupancy requirement — property owner does not need to live on the lot to build or rent an ADU · Source
Requires municipalities to allow at least one ADU on residential lots with single-family dwellings · Source
Prohibits minimum lot size requirements for ADUs that exceed 50% of the existing lot size · Source
Limits rear and side setback requirements to a maximum of 5 feet for ADUs · Source
Prohibits municipalities from requiring additional off-street parking spaces for ADUs · Source
Applies to municipalities with populations over 5,000 — covers all major Arizona cities · Source
Partial preemption — cities retain authority over design standards, height limits, and maximum unit size within state-defined bounds · Source
Legislative History
2024 — Arizona HB 2720 · Verified June 25, 2026 · Source
Arizona Governor Katie Hobbs signed HB 2297 into law. The bill provides partial state preemption of local ADU regulations, effective September 14, 2024. Cities with populations over 5,000 must update their local ADU ordinances to comply. Phoenix, Tucson, Mesa, Chandler, Scottsdale, and all major Arizona cities are affected. · Source
2016 — Arizona SB 1350 · Verified June 25, 2026 · Source
Arizona preempted local governments from prohibiting short-term rentals outright. Later amended by SB 1168 (2022) to restore some local regulatory authority including registration requirements, safety standards, and nuisance enforcement. · Source
Official Sources
What Does Preemption Mean for Local Cities?
Because Arizona law preempts local ordinances, individual cities cannot impose restrictions stricter than the state standard. A city may still have additional administrative requirements, but cannot deny ADU applications that comply with state minimums.
Learn about Arizonazoning preemption →Source: Arizona House Bill 2720 (HB 2720) — Accessory Dwelling Units; Requirements. Last verified April 5, 2026. View source