State law forces Provo to allow external ADUs on larger lots; parking rules loosened

Malia Daly, a Provo city policy analyst, told the East District meeting that SB284 requires cities designated as moderate-income housing jurisdictions to revise local rules so external accessory dwelling units (ADUs) are permitted on residential parcels of at least 11,000 square feet. “By October 1st, all cities that are moderate income housing cities…have to change our code to allow external ADUs,” Daly said.

Daly said many existing local ADU regulations will remain in force: owner occupancy requirements, a prohibition on short-term rentals, building-height and footprint limits that ensure an ADU is smaller than the primary dwelling, permanent foundations and separate utility hookups, and the need for a rental-dwelling license and inspections. “There’s a lot of requirements that go along with qualifying for [a] rental dwelling license including health and safety standards…regular checks and inspections for fire and building code,” Daly said.

She highlighted two state-driven changes. First, external ADUs will be allowed on any residential parcel 11,000 square feet or larger where ADUs are otherwise permitted; second, the state limits how much local governments can require for off-street parking: an external ADU of 650 square feet or more can require up to two off-street stalls; an ADU under 650 square feet may require only one. Daly summarized: “If it’s an external ADU, you can only require a maximum of two [parking stalls]…if it’s smaller than 650, you can only require one.”

Residents at the meeting pushed back with enforcement questions. One attendee pressed staff on how setback exceptions and permitted construction storage on private lots have been handled; a long-time Foothills resident asked what prevents property owners from seeking exemptions or zoning changes to circumvent local protections. Councilor Willock responded that the change stems from state statute, not a city initiative, and urged residents to use code-enforcement channels when they see problems: “This was not proposed by the city…this was a state law that got passed in the recent legislative session,” he said, and added that residents should report suspected violations so enforcement staff can investigate.

Daly and staff also said the city will develop an interactive parcel map showing where external ADUs will be allowed and will follow normal permitting, inspection and impact-fee rules for detached units. She emphasized that internal ADU rules (basements and units inside primary dwellings) will not change under this required, narrow update. The ordinance update to align Provo code with SB284 must be completed by Oct. 1; the council expects further zoning discussions over the summer.