ADU Rules in Mesa, Arizona
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ADU Rules in Mesa, Arizona
Arizona's casita statute is HB 2720 (2024), codified at A.R.S. §9-461.18, applying to cities with 75,000+ population. HB 2673 is unrelated.
Permitted ADU Types
- Detached ADU: Standalone structure on the lot
- Attached ADU: Addition to primary dwelling with own entrance
- Garage Conversion: Converting existing garage to dwelling unit
Size Limits
| ADU Type | Maximum Size |
|---|---|
| Detached ADU | 1,000 sq ft or 50% of primary dwelling |
| Attached ADU | 50% of primary dwelling floor area |
| Garage Conversion | Existing footprint |
Setbacks
- Front: Base zone standard (typically 20–25 ft)
- Side: 5 feet minimum
- Rear: 5–10 feet minimum
Height
- Detached ADU: Maximum 18 feet
- Cannot exceed primary dwelling height
Parking
One additional off-street parking space required per ADU.
Permit Process
- Check zoning: Verify at Mesa Development Services
- Submit plans: Architectural and site plans
- Review: Zoning and building review
- Building permit: Issued after approval
- Inspections: All required phases
- Certificate of Occupancy: Required before occupancy
Contact
Mesa Development Services 55 N. Center Street, Mesa, AZ 85201 Phone: (480) 644-4273 Website: mesaaz.gov/business/development-services
Disclaimer: Verify current requirements with Mesa Development Services before starting any project.
More about Mesa Zoning
Sources
- Mesa Zoning Ordinance — Residential Districts·library.municode.com·Accessed 2026-04-07·Direct link
- City of Mesa Development Services·mesaaz.gov·Accessed 2026-04-07·Direct link
- A.R.S. § 9-461.18 — Accessory dwelling units (HB 2720, 2024)·azleg.gov·Accessed 2026-05-24·Direct link
FAQ
Are ADUs allowed in Mesa, Arizona?
Yes. Mesa permits accessory dwelling units in single-family residential zones. Arizona HB 2720 (2024), codified at A.R.S. § 9-461.18, requires municipalities over 75,000 population (Mesa qualifies) to allow at least one attached and one detached ADU on single-family lots; statewide setbacks may not exceed 5 ft from rear/side property lines.
What is the maximum ADU size in Mesa?
Under Arizona A.R.S. § 9-461.18, an ADU may be up to 75% of the primary dwelling's gross floor area or 1,000 sq ft, whichever is less. Verify Mesa's local implementing ordinance with the Development Services Department.
Does Mesa require owner occupancy for an ADU?
Verify with Mesa Development Services. A.R.S. § 9-461.18 prohibits municipalities from requiring a familial, marital, employment, or other preexisting relationship between the owner of the single-family dwelling and the occupant of an ADU.
Disclaimer: The information on this website is provided for general informational purposes only and does not constitute legal, financial, or professional advice. Always verify current requirements with your local planning department.