ADU Regulations in Flagstaff, Arizona
At 7,000 feet in Coconino County, Flagstaff permits ADUs under local ordinance with a focus on rental housing affordability. The mountain climate influences building standards for accessory units.
Below is a summary of the key zoning rules applicable to Accessory Dwelling Units in Flagstaff as of 2026. Regulations are governed by local zoning ordinances, as Arizona has no statewide ADU mandate.
| Regulation | Requirement |
|---|---|
| Maximum Size | 1,000 sq ft |
| Property Setbacks | 5 ft rear, 5 ft side |
| Extra Parking Required | Required (1 space) |
| Owner Occupancy | Not required |
Additional Local Requirements for Flagstaff
- ADU allowed in residential zones per local ordinance
- Minimum 200 sq ft
- Building permit required
- ⚠️ AZ has NO statewide ADU law — city code governs
📥 Download the Complete Flagstaff ADU Cheat Sheet
Get the step-by-step permit checklist, official government forms, direct planning department contacts, and estimated fees — all in one printable PDF for Flagstaff, Arizona.
Download the Complete Flagstaff ADU Cheat Sheet — $12Frequently Asked Questions About ADUs in Flagstaff
Can I build an ADU in Flagstaff?
This Arizona city permits ADUs under local ordinance. Confirm your zone's eligibility with the planning department first.
How big can my ADU be in Flagstaff?
What is the maximum ADU size allowed in Flagstaff? ADUs in Flagstaff can be up to 1,000 square feet, subject to the property's zoning and lot coverage limits. Always confirm the exact allowed size with the Flagstaff planning department before designing your project.
What about setbacks and other requirements in Flagstaff?
What are the setback requirements for an ADU in Flagstaff? ADUs in Flagstaff generally require setbacks of 5 ft rear, 5 ft side. California state law (AB 68) limits local setback requirements to 4 feet for existing structures, but always verify with local zoning.
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