Yuma, AZ Accessory Structures: ADU Rules (2026)
ADU rules in Yuma, AZ, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.
Key Facts
- Units allowed
- 1 per lot; 2 if lot is 10,000+ sq ft
- Minimum unit size
- 100 square feet
- Maximum unit size
- 50% of primary home's floor area
- Carriage house height cap
- 25 feet
- Extra lot coverage allowed
- +5%
- Adopted
- Ord. O2017-013 (2017); amended 2023, 2025
Summary
Yuma allows one accessory dwelling unit behind a single-family home in residential zones, or two on lots of 10,000 square feet or larger, with one attached to the house and the other detached. Each unit must be at least 100 square feet and no bigger than half the primary home's floor area.
(A) Applicability. An accessory dwelling is permitted as a subordinate to an existing or planned single-family dwelling unit (primary residence), provided that the provisions below are met. ... (1) Use. Permitted on certain residentially zoned properties which currently have or will have a single-family residence. Only one unit will be permitted for each property, unless the subject property measures 10,000 square feet or greater in size in which case a second unit may be permitted. ... (5) Unit size. (a) Each accessory dwelling shall have a minimum size of 100 square feet. (b) The maximum permitted size of an accessory dwelling shall not exceed 50% of the total square footage of the entire structure of the primary residence to include all covered area.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-74: Current through May 20, 2026).
Full Breakdown
16(C) permits an accessory dwelling only as a subordinate use to an existing or planned single-family residence. One unit is allowed per lot; a second is allowed once the lot reaches 10,000 square feet, and when two units exist one must be attached and the other detached. Accessory dwellings can add 5% to the district's normal lot coverage limit, and detached units must sit behind the midpoint of the primary residence while meeting the district's side and rear setbacks (an alley-accessed unit can reduce its rear setback to five feet).
Height is capped at the height of the primary house, with a hard 25-foot ceiling for units built above a detached garage as a carriage house or garage apartment. A second unit triggers an added off-street parking space, which can sit within the front setback. Design must match the primary residence's colors, materials and detailing, and units in a historic district need Design and Historic Review Commission approval, with design disputes appealable to the Planning and Zoning Commission. 16(C)(9) by filing an application and allowing a city inspection for fire, life-safety and health compliance; until approved they remain non-conforming.
Violations & Fines
An accessory dwelling built or occupied outside these standards is a zoning violation under §154-999, a class 1 misdemeanor carrying a fine up to $1,000, up to ten days' imprisonment, or both, with each day of continued violation treated as a separate offense. A pre-existing unit that never files for legalization stays non-conforming indefinitely under §154-15.16(C)(9)(c).
Frequently Asked Questions
How many accessory dwelling units can I build in Yuma?
How big can a Yuma ADU be?
Do I need special approval for an ADU in a historic district?
What if I already have an unpermitted accessory unit?
Sources & Official References
Other rules in Yuma
How Yuma compares: Easiest Cities to Build an ADU·Compare Yuma to another location·View the Arizona accessory structures overview
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