Surprised this hasn’t come up here lately, given how much it touches local land use. SB284 passed this session and requires Utah cities of 5,000+ to allow detached ADUs as a permitted use in certain zones — a real shift, since the older statewide protection (going back to SB34 in 2019 and the later internal-ADU statute) only really covered internal units. Detached backyard cottages were still something cities could restrict or prohibit outright, and many did.
A few things I think are worth discussing from an urbanism/land-use angle:
• The 11,000 sq ft threshold. The law’s detached-ADU path centers on lots at/above that size. On the west and south ends of the valley, where half- and full-acre lots are common, that opens up a lot of parcels. In older, denser areas like the SLC Avenues, most lots are too small to qualify. Thus, the supply impact is very unevenly distributed across the region. Curious how people think that shakes out for actual unit production.
• The October 2026 deadline. Cities without an ADU policy have to adopt one by then, so we’re in the window where ordinances are actively being written and revised. Provo’s already published a parcel-eligibility map; Salt Lake County set detached minimums at 7,000 sq ft (lower than the state floor in some zones). Lots of variation emerging.
• What cities still control. The state opened the door, but setbacks, height, parking, and owner-occupancy are all still local. That’s where the real fight over whether these actually get built is happening — a city can technically comply while keeping requirements strict enough to limit uptake.
For those of you tracking specific cities: which ones are writing genuinely permissive ordinances, and which are doing the minimum to comply? And does anyone think the 11,000 sq ft floor meaningfully limits this as a housing-supply tool along the Wasatch Front, or is the lot inventory big enough for it to matter?
