Accessory Structures in Tucson, AZ: What Residents Actually Need to Know
If you live in Tucson or are thinking about moving there, accessory structures are one of those things you probably won't think about until they affect you directly. Tucson has 2 specific rules on the books covering different aspects of accessory structures, and some of them might surprise you.
ADU Rules
Tucson's UDC allows up to two accessory dwelling units per single-family parcel, one on a duplex lot, without counting them against density limits or requiring extra parking. Each ADU is capped at 75% of the principal home's floor area or 1,000 square feet, whichever is smaller, though any ADU may reach 650 square feet regardless of house size.
Key details: ADUs permitted per single-family parcel: 2 (1 on duplex lots). Max ADU size: Lesser of 75% of house or 1,000 sf. Flat size allowance regardless of house size: Up to 650 square feet. ADU side/rear setback: 5 feet. Parking requirement: None required for ADUs.
An ADU built beyond the permitted count, oversized, or missing its required setback is a UDC violation subject to Article 10 enforcement. The Zoning Administrator can issue a correction notice, cite the owner under Chapter 8 of the Tucson Code, or refer the matter to the City Attorney for a restraining or abatement action. An affordable-unit ADU that loses its deed restriction forfeits the density bonus that authorized the extra unit.
Shed & Carport Rules
Tucson exempts only tiny sheds, five feet tall and ten square feet or less, from zoning review; anything bigger is an accessory building under UDC Sec. 6.6.2 and must meet the principal use's setbacks, plus a 12-foot height cap under Sec. 6.6.3.D unless it's attached to the house.
Key details: Zoning-exempt shed size: 5 ft tall, 10 sq ft or less. Exempt animal shelter size: 6 ft tall, 16 sq ft or less. Detached accessory structure height cap: 12 feet (Sec. 6.6.3.D). Setback rule: Follows principal building's perimeter yard. Parcel-line exception: Allowed with adjoining owner's consent.
A shed built without meeting the setback or 12-foot height limit is a zoning code violation subject to Tucson's standard UDC enforcement and penalty process under Article 10 (Enforcement and Penalties), which can require the structure be brought into compliance, permitted retroactively, or removed. Because the UDC ties a shed's setback to the underlying zone's dimensional standards, the safe route is confirming the applicable perimeter yard for the specific zone before building.
The Bottom Line
Tucson's accessory structures rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Tucson is broadly strict or permissive.
These rules come from Tucson's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.