■ ZONE-LEVEL RULES + SETBACKS ■
ADU Rules in Tucson, AZ
Arizona requires larger cities to allow ADUs on single-family lots. In Tucson, most residential zones allow an ADU up to 1,000-1,500 sq ft depending on zone, and recent state law opens the door to multiple units on one lot.
LAW: AZ HB 2720 (2024) + Tucson Unified Development Code · PRIMARY SOURCE
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Zone-by-zone rules (size caps, setbacks, height) codified from the Tucson UDC, applied to your parcel's actual zoning from Pima County public GIS records.
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Tucson, AZ ADU Questions
Are ADUs legal in Tucson?
Yes. Most Tucson residential zones (R-1, R-2, R-3, CR-1 and others) allow an ADU, attached or detached, with size caps between 1,000 and 1,500 sq ft depending on the zone. Enter your address and we'll check your exact zone.
How big can an ADU be in Tucson?
In R-1/R-2/R-3 zones, up to 1,000 sq ft (capped at 75% of the primary residence's square footage). In CR-1, GR-1, SR and similar zones, up to 1,500 sq ft (capped at 70%). Some zones use a percentage-of-lot formula.
Can I build two ADUs on one lot in Tucson?
In many zones, yes — Arizona HB 2720 allows two ADUs, and the HB 2721 Middle Housing Initiative can allow up to four total structures on qualifying lots. Zone-specific limits apply.