What is HB 2720, and how does it affect my casita or ADU in Phoenix?

Arizona House Bill 2720, signed in 2024 and codified in ARS 9-461.18, preempts municipal zoning that previously blocked accessory dwelling units (ADUs, often called casitas in Arizona). The statute applies to every Arizona municipality with a population over 75,000 — which includes Phoenix, Mesa, Tucson, Chandler, Glendale, Scottsdale, Gilbert, Tempe, Peoria, and Surprise — and it requires those cities to permit at least one detached ADU and one attached ADU on every lot zoned for single-family residential use.

What HB 2720 prohibits is just as important as what it allows. Cities can no longer require: owner-occupancy of either the primary dwelling or the ADU, off-street parking specific to the ADU when the lot is within one half mile of major transit, separate utility connections, design review beyond what applies to the primary structure, or minimum lot sizes greater than the underlying zone allows. Maximum ADU size must be at least 1,000 square feet or 75 percent of the primary dwelling, whichever is less.

What HB 2720 does not preempt: setbacks, height limits inside the underlying zone, building code compliance, floodplain rules, septic capacity, fire-flow requirements, and — critically — private CC&Rs enforced by an HOA. About 60 percent of Phoenix-metro homes sit inside a planned community, and HOA architectural restrictions written before HB 2720 still bind owners under ARS 33-1803 unless the association affirmatively amends them.

Phoenix updated its zoning ordinance in late 2024 to align with the statute, adopting Section 608 of the Phoenix Zoning Ordinance for ADUs. Permit-ready casita plans typically clear PDD plan review in three to five weeks, with sub-trade permits issuing within a week of the parent. Connection fees for water, sewer, and impact fees still apply at the standard residential schedule, but the city cannot levy an ADU-specific surcharge after HB 2720.

If your HOA refuses ADU approval, you have the right to challenge under ARS 33-1817 reasonableness review, but litigation is slow. Read your CC&Rs first.