Salt Lake County · Service area
Salt Lake City already allows ADUs. The new law removes the discretion.
Already allowed The statute removes the discretion.
Takes about 3 minutes. No email required to see your result.
Salt Lake City has permitted accessory dwelling units under 21A.40.200 for years. What S.B. 284 adds is that on a qualifying lot the city may no longer require a conditional use permit for a detached unit in a primarily residential zone, and its parking demand is capped by statute.
“A specified municipality shall adopt a land use regulation that permits a detached accessory dwelling unit on any lot or parcel that is 11,000 square feet or larger…” — S.B. 284, Enrolled Copy, Utah Code § 10-21-304, effective October 1, 2026.
The numbers that decide your project
| Rule | Salt Lake City — 21A.40.200 |
|---|---|
| Maximum size | Detached units limited to 1,000 sq ft of floor area. State law separately bars any ADU larger than the main house. confirm with city |
| Height | 17 ft base for detached. Up to 24 ft pitched / 20 ft flat if side and rear setbacks increase 1 ft for every additional foot above 17. confirm with city |
| Side & rear setbacks | Minimum 3 ft for a detached unit, increasing with height as above. confirm with city |
| Parking | 1 space — waived within ¼ mile of a transit stop, ½ mile of a city-designated bike route, or in districts with no off-street minimum. confirm with city |
| Owner occupancy | Required. confirm with city |
state law Quoted from the enrolled copy of S.B. 284 — primary source, verified.
confirm with city From the city's published ADU material or council reporting — Arena confirms at the planning counter before design.
moving now The city is actively amending this ahead of October 1, 2026. Treat as a moving target.
We would rather show you the gap than guess. Arena is a builder, not a law firm — confirm your parcel with Salt Lake City before you sign anything.
What that means on your lot
That single number decides whether the new state law applies to you. Enter your address above — we'll tell you which rule you fall under and which plans fit, in about three minutes.
Arena publishes every price — seven plans from The Lookout at 735 sq ft to The Launchpad at 2,541 sq ft. One team owns design, engineering, permitting and construction.
From $128,625 · see every price →
Plans that fit a Salt Lake City backyard
Permitting queues in Salt Lake City will not get shorter after October 1.