Salt Lake County · Service area

Can you build a backyard home in Cottonwood Heights?

Today a detached ADU here is a conditional use. On October 1 that becomes illegal.

Conditional use today The statute prohibits exactly this.

Takes about 3 minutes. No email required to see your result.

What changed here on October 1

Today a detached ADU here is a conditional use. On October 1 that becomes illegal.

Cottonwood Heights currently allows internal ADUs as a permitted use but routes detached ADUs through a conditional use process in its R-1, RR-1 and F-1 zones. Section 10-21-304 expressly bars a city from requiring a conditional use permit for a detached ADU in a primarily residential zone. This is one of the clearest before-and-after changes on the Wasatch Front.

“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

Cottonwood Heights ADU rules at a glance

Rule	Cottonwood Heights — Cottonwood Heights 19.75
Detached ADUs today	Conditional use in R-1, RR-1 and F-1 zones — discretionary approval required. confirm with city
Detached ADUs from Oct 1	Conditional use permit prohibited for a qualifying detached ADU in a primarily residential zone. state law
Internal ADUs	Permitted use on lots of 6,000 sq ft or more in R-1, RR-1 and F-1. confirm with city
Owner occupancy	Record owner must occupy either the primary dwelling or the ADU as a permanent residence, with proof at application. confirm with city
Parking	One additional non-tandem stall per ADU, on top of the two off-street stalls every single-family property must have. confirm with city
Short-term rental	Prohibited under 19.75.050.B. 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 still bringing this into line with the law that took effect 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 Cottonwood Heights before you sign anything.

What that means on your lot

If you were quoted a conditional use process in Cottonwood Heights this year, get a second answer after October 1.

Is my Cottonwood Heights lot 11,000 sq ft?

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.

Quoted on your Cottonwood Heights lot

Eight plans, from The Lookout at 784 sq ft to The Launchpad at 3,061 sq ft. A plan that is one component stack shows that price. The others say request a quote.

ADU calculator → · How the price works →

Can you build a backyard home in Cottonwood Heights?

Today a detached ADU here is a conditional use. On October 1 that becomes illegal.

Cottonwood Heights ADU rules at a glance

If you were quoted a conditional use process in Cottonwood Heights this year, get a second answer after October 1.

Is my Cottonwood Heights lot 11,000 sq ft?

Quoted on your Cottonwood Heights lot

Three places to start

The Lookout

The Encore

The Loft

There's still $2,200 a month hiding in your house.