accessory dwelling units; population; regulations

Arizona municipalities with populations over 75,000 must allow accessory dwelling units (ADUs) on single-family residential lots by January 1, 2025. The law requires at least one attached and one detached ADU per lot, with larger parcels (1+ acres) needing one affordable ADU for households earning ≤80% of area median income. Municipalities cannot ban separate rentals, require design matching, impose extra fees, or restrict ADUs more strictly than single-family homes. Failure to adopt compliant regulations by the deadline means ADUs become universally permitted without restrictions on all residential lots in that municipality.