Salt Lake County · Service area
Herriman is still writing its detached ADU ordinance — and the clock runs out October 1.
Ordinance still in draft The state floor applies regardless.
Takes about 3 minutes. No email required to see your result.
Herriman's planning commission was still debating a detached ADU draft into early 2026, sending it back to staff over height, parking and privacy. Whatever the city lands on, § 10-21-304 sets the floor from October 1: a detached unit becomes a permitted use on qualifying lots, with no conditional use permit.
“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 | Herriman — Draft ordinance — not yet final |
|---|---|
| Status | Detached ADU ordinance was in draft and continued by the planning commission in early 2026. Moving target. moving now |
| Proposed size | Draft capped the ADU at 1,000 sq ft or 50% of the primary residence, whichever is smaller. moving now |
| Proposed minimum lot | Draft proposed detached ADUs citywide on lots of 6,000 sq ft and up — below the state threshold. moving now |
| Owner occupancy | Included in the draft. moving now |
| Height, parking, privacy | The specific points the commission sent back for revision. moving now |
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 Herriman 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.
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Plans that fit a Herriman backyard
Permitting queues in Herriman will not get shorter after October 1.