Utah County · Service area
Lehi has already passed its new rules — and eligibility jumped about 20%.
New rules already passed Ahead of the deadline.
Takes about 3 minutes. No email required to see your result.
Lehi is ahead of the deadline. The city council approved a compliant detached ADU policy in July 2026, replacing a 14,520 sq ft minimum lot and a 1,300 sq ft cap. Lehi's own community development director estimated the change increases eligibility upwards of 20%.
“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 | Lehi — Lehi Development Code — amended July 2026 |
|---|---|
| Old minimum lot | 14,520 sq ft — now superseded by the state's 11,000 sq ft threshold. confirm with city |
| Old size cap | Dwelling portion could not exceed 1,300 sq ft. confirm with city |
| New setback | Detached unit must sit 6 ft from the existing home. confirm with city |
| Owner occupancy | Required in either the primary home or the detached unit. confirm with city |
| Old parking | Two off-street stalls; state law now caps demand at two (≥ 650 sq ft) or one (under 650 sq ft). state law |
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 Lehi 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 Lehi backyard
Permitting queues in Lehi will not get shorter after October 1.