Can I build an ADU in Utah? Check your home
Six questions about your home and lot. You get what Utah law says about your kind of unit, and what your city still decides.
Your result
General information from the official and published sources below, not a ruling on your property.
Planning an ADU?
How the adu checker works
The checker applies two state rules. Utah's internal ADU law (Utah Code 10-21-303) covers units inside an owner-occupied, detached single-family home. SB 284 (2026) covers detached units on single-family lots of 11,000 square feet or more in cities of 5,000 or more people. Anything outside those rules is up to your city's ordinance.
It's general information, not legal advice. Confirm current rules with your city's planning department. Our SB 284 guide has more detail.
Sources
Common questions
Do I have to live in the house to add an ADU in Utah?
For an internal ADU, yes: the state rules cover homes occupied as the owner's primary residence. For a detached ADU, your city may require it; Utah courts have upheld owner-occupancy conditions on accessory dwellings.
Do I pay impact fees on an internal ADU?
No. Utah law exempts building an internal ADU from impact fees. Building, health and fire codes still apply, so the work still has to meet code.
Can my HOA stop me from renting an ADU?
Not an internal ADU that meets local land use rules and building, health and fire codes: Utah law says an HOA can't prohibit renting it. For detached units, read your CC&Rs and your city's rules.