Can you build an ADU in Tucson, AZ?
The city explicitly states ADUs are permitted on residential lots / in zones that allow residential uses, and Tucson adopted additional 2024 amendments removing minimum parking requirements and relaxing other barriers.
Confidence: high · Last researched May 2026
ADU rules
Accessory dwelling units, also called casitas, are permitted on residential lots in Tucson, subject to city regulations. Tucson first allowed them citywide on residential lots in late 2021, and the Mayor and Council adopted additional amendments in October 2024 to comply with state law and remove or relax several prior constraints.
- ADUs are permitted on residential lots / in zones that allow residential uses
- 2024 amendments increased the number of ADUs allowed per lot
- 2024 amendments changed how the maximum size of an ADU is calculated
- 2024 amendments adjusted ADU height limits
- 2024 amendments removed minimum parking requirements
- 2024 amendments amended minimum setbacks
- City page describing the earlier framework said maximum size was up to 10% of lot size, up to 1,000 square feet, with all lots allowed at least 650 square feet
- City page describing the earlier framework said maximum height was 12' or the height of the primary structure on lots with two-story homes
- City page describing the earlier framework said each newly constructed ADU would be required to have a cool roof
Dimensional standards in Tucson, AZ
| RH — minimum lot area | 180,000 sq ft |
| SR — minimum lot area | 144,000 sq ft |
| SH — minimum lot area | 36,000 sq ft |
| RX-1 — minimum lot area | 36,000 sq ft |
| RX-2 — minimum lot area | 16,000 sq ft |
| R-1 — minimum lot area | SF: 7,000 |
| R-2 — minimum lot area | 5,000 |
| R-3 — minimum lot area | SF: 5,000 |
| MH-1 — minimum lot area | SF/MH: 7,000 |
| MH-2 — minimum lot area | SF/MH: 5,000 |
| O-1 — minimum lot area | RES: 7,000; NON: 10,000 |
| O-2 — minimum lot area | RES: 5,000; NON: 0 |
| O-3 — minimum lot area | RES: 5,000; NON: 0 |
| C-1 — minimum lot area | 0 |
| C-2 — minimum lot area | 0 |
| C-3 — minimum lot area | 0 |
Related questions
Are ADUs allowed in Tucson, AZ?
Accessory dwelling units, also called casitas, are permitted on residential lots in Tucson, subject to city regulations. Tucson first allowed them citywide on residential lots in late 2021, and the Mayor and Council adopted additional amendments in October 2024 to comply with state law and remove or relax several prior…
Full investor analysis
You've seen the general rule. The full Tucson, AZ report shows which districts allow ADUs by-right vs. by special permit, the approval path and timeline, and the overlay/flood constraints that quietly kill ADU projects here. First town report is free.
Get the full Tucson, AZ report free →More about Tucson, AZ zoning
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This summary is AI-generated from public municipal sources and is not legal, engineering, or land-use advice. Always verify zoning with Tucson, AZ officials before making decisions.
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