Arizona · AZ
ADU laws & builders in Arizona
Arizona is an emerging ADU market, with Phoenix and Tucson leading on permit pathways. Most builds happen as detached ADUs or casitas on larger suburban lots. Builder density is lower than the coasts, so leads are matched to the most relevant specialist rather than auctioned to multiple.
Last reviewed: 2026-05-29
Are ADUs legal in Arizona?
Yes, with rules set locally. Arizona has no statewide ADU mandate, but Phoenix and Tucson have both moved to make ADUs (often called 'casitas' or 'guest houses' here) easier to permit, and the market is growing quickly. Larger suburban lots across the Valley make detached casitas a natural fit.
Key rules that affect your build
Phoenix and Tucson each set their own size limits, setbacks, and whether the unit can be rented. Because adoption is newer and builder density is lower than on the coasts, the most important step is matching with a builder who has actually permitted casitas in your specific city.
Cost and timeline in Arizona
A permitted detached casita in the Phoenix or Tucson metro generally runs $160K–$330K turnkey. Plan on 7–12 months. Because qualified ADU builders are more limited here, we match Arizona leads to the single best-fit specialist rather than auctioning to several.
Official source
We summarize Arizona's ADU rules in plain English. For the authoritative, always-current legal detail, go straight to the source:
City of Phoenix — Planning & DevelopmentAlways verify current rules with the official source before making decisions.
Pre-approved ADU plan programs in Arizona
- Phoenix — Phoenix Casita Permitting
- Tucson — Tucson ADU Permitting
Find a verified ADU builder in Arizona
Tell us about your project and we'll match you with the best-fit verified builder who know Arizona's rules and pre-approved plan programs — free, no obligation.
Get matched in ArizonaSee also our ADU FAQ and how we verify builders.