Detached accessory dwelling unit ordinance
New rules required by state law allowing backyard homes on single-family lots of 11,000 square feet or more, with parking, setback, materials, owner-occupancy and 90-day minimum rental standards. The Planning Commission recommended it 7-0 Sept. 16 with changes; the council adopted it Sept. 22 and plans further work-session review.
- Where it stands
- Approved
- Type
- Code change
- Location
- Citywide
- Applicant
- American Fork City
Every hearing and vote
July 19, 2022 · City Council work session
Detached accessory dwelling units
Discussed
Legal counsel Cherylyn Egner outlined a draft: owner occupancy, single-family lots in approved zones, a permit and recorded notice, no short-term rentals, one per lot, not sold separately, impact fees and separate utilities, one parking space. Barnes said it solved a problem that didn't exist; Carroll and Hunter wanted guidance written. Egner will start with a 12,000-square-foot minimum lot and two-bedroom maximum.
- Draft minimum lot: 12,000 sq ft
- Max bedrooms: 2
September 27, 2022 · City Council
Moderate-income housing element of the general plan
Approved · 5-0
Adopted the state-required moderate-income housing element; City Planner Patrick O'Brien said strategies were chosen to match existing city direction, with the Station Area Plan first, and failing to meet goals could cost state funding and grants. Shelton moved to move detached accessory dwelling units to year one; the motion died for lack of a second.
October 1, 2024 · City Council work session
Detached accessory dwelling units
Discussed
Development Services Director Patrick O'Brien said the moderate-income housing plan calls for easing ADU rules and laid out choices on size, setbacks, height, parking, utilities, lot size, owner occupancy and short-term rentals. Councilmember Staci Carroll noted the council has refused to let accessory structures become dwellings. Councilmembers Clark Taylor, Ryan Hunter and Ernie John said the city has done its part on density; Carroll and Tim Holley wanted options rather than a blanket no. The council opposed short-term rentals in ADUs.
August 4, 2026 · City Council work session
Accessory dwelling unit code amendment
Continued
Postponed to a later work session because Councilmembers Carroll and Taylor had left.
August 18, 2026 · City Council work session
Detached accessory dwelling unit ordinance
Discussed
Development Services Director Patrick O'Brien walked through a draft ordinance required by state law permitting detached ADUs on single-family lots of at least 11,000 square feet. The city may regulate height, setbacks, lot coverage, size, owner occupancy, short-term rentals and fees, and may require only one parking space for units of 650 square feet or less and two for larger units. Council members discussed limiting one ADU per lot (internal or detached), owner occupancy, height and story limits, requiring materials 'compatible' with the main home, front-yard placement, fire access and impact fees. Consensus was to send a revised draft to the Planning Commission before the Oct. 1 state deadline.
- State deadline: Oct. 1, 2026
- Minimum lot: 11,000 sq. ft.
September 16, 2026 · Planning Commission
"A" definitions: accessory buildings, dwellings and structures (Section 17.12.201)
Recommended for approval · 7-0
Staff-initiated definitions to remove ambiguity between accessory buildings, accessory dwellings and accessory structures, in preparation for detached ADU rules. No public comment.
- Initiated by: city staff
September 16, 2026 · Planning Commission
"D" definitions: detached accessory dwelling unit (Section 17.12.204)
Recommended for approval · 7-0
Staff-initiated definition of a detached accessory dwelling unit. No public comment.
- Initiated by: city staff
September 16, 2026 · Planning Commission
Detached accessory dwelling unit regulations (new Section 17.5.136)
Recommended for approval · 7-0
Patrick O'Brien said Utah Code 10-21-304 requires cities to allow detached ADUs on single-family lots of 11,000 square feet or more, with limits on what cities may regulate, and the city must have rules in place by Oct. 1. The draft sets setbacks, height, maximum size, location, materials (no galvanized, corrugated or ribbed metal facades), parking (one added stall for units up to 600 square feet, up to two for larger units), owner occupancy of one of the two units, a 90-day minimum rental to bar short-term rentals, utility capacity and fees, and administrative review by the Development Review Committee; a lot may have an internal or a detached ADU but not both. Commissioners added: parking must be off-street on the lot (no right-of-way, no cross-parking agreements), no tandem parking, DADUs allowed in side yards without a variance if setbacks are met, a 10-foot wall-to-wall separation from the main house, and a typo fix. Commissioner Harold Dudley voiced reservations about side-yard units. The City Council adopted the ordinance 4-0 on Sept. 22.
- Initiated by: city staff
- State law: Utah Code 10-21-304; deadline Oct. 1, 2026
- Eligible lots: single-family, 11,000 sq ft or more
- Minimum rental: 90 days
- Commission changes: off-street parking on same lot, no tandem parking, side yards allowed, 10-ft separation from home
- Council adopted Ordinance 2026-09-21 on Sept. 22, 4-0 (Councilmember Clark Taylor absent)
September 22, 2026 · City Council
Detached accessory dwelling unit ordinance (Section 17.5.136)
Approved · 4-0
Ordinance 2026-09-21, required by Utah Code 10-21-304 by Oct. 1, allows a detached ADU on lots of at least 11,000 square feet with a single-family home. The unit's footprint may not exceed 1,500 square feet or the main home's footprint, nor be taller than the main house or 24 feet; side and rear setbacks are generally 12 feet (20 feet on a corner street side); with other accessory buildings it may cover no more than 25% of the rear yard. One on-site parking space is required under 650 square feet and two otherwise; an owner must live on site, only one ADU per lot is allowed, and rentals under 90 days are barred. The Planning Commission recommended approval unanimously Sept. 16. Councilmember Staci Carroll questioned 24-foot units at 12-foot setbacks; Councilmember Ernie John raised neighborhood fit and water and sewer capacity in older areas; Councilmember Ryan Hunter wanted more discussion of tandem parking. Members listed height, tandem parking, utilities, impact fees and water dedication for a future work session.
- Ordinance No. 2026-09-21
- Planning Commission recommended approval unanimously, Sept. 16, 2026