The Arizona Casita Guide
Rules, costs, and financing for building a casita in Arizona.
Arizona's new state law changed what cities can require for accessory dwelling units. Here's what actually applies to your lot, what it'll really cost, and how to pay for it — written by a licensed Arizona loan officer, not a contractor.
2024–2025 Law Change
Arizona now requires most cities to allow casitas — with real limits on what they can demand.
HB 2720 (signed May 2024, effective January 1, 2025) requires cities over 75,000 people to allow at least one attached and one detached ADU on any single-family lot. HB 2928 (May 2025) extends similar rules to county-controlled land. Cities can't demand extra parking, owner-occupancy, matching materials, or setbacks greater than five feet.
Read the full explainer →Start here
The New Arizona Casita Law
HB 2720 (2024) and HB 2928 (2025) in plain English — what cities can and can't require.
Read →Can my HOA block my casita?
The state law limits cities. It does not override private HOA covenants. Here's what to check.
Read →What a casita really costs
Detached builds typically run $150K–$300K in metro Phoenix. Attached units can start much lower.
Read →How to pay for it
HELOC, cash-out refi, renovation, and construction loans — how each works for a casita build.
Read →Phoenix
How the state ADU law applies in Phoenix.
Read →Mesa
How the state ADU law applies in Mesa.
Read →Scottsdale
How the state ADU law applies in Scottsdale.
Read →Tucson
How the state ADU law applies in Tucson.
Read →Who's writing this
Got a specific question?
Two paths: get matched with a builder, or ask a financing question.