ADU Regulations in Utah (UT)
Utah is rated Moderate for ADU construction with an ADU-friendliness score of 50/100 (Moderate). Utah has a statewide ADU law that sets baseline rules across all municipalities. Owner must reside on the property. Additional parking may be required. Utah passed SB 174 in 2021, requiring municipalities to allow at least one type of ADU (internal, attached, or detached) on single-family lots. However, cities retain significant discretion on which type they allow and can impose conditions. Salt Lake City has the most permissive ADU policies in the state.
Full ADU Regulations Summary for Utah
| ADUs Allowed | Yes |
| Statewide ADU Law | Yes |
| Maximum ADU Size | Set locally |
| Owner Occupancy Required | Yes |
| Parking Required | Yes |
| Minimum Setback | Set locally |
| Permitting Timeline | Varies by municipality |
| Impact Fees | Varies by municipality |
| Long-Term Rental Allowed | Yes |
| Short-Term Rental (Airbnb) Allowed | Yes |
| Ease of Building | Moderate |
ADU Regulations by City in Utah
ADU rules can vary by city even within the same state. While Utah's statewide law sets minimum standards, some cities have additional local provisions. Below are ADU details for 3 cities in Utah.
Salt Lake City
ADUs allowed on most residential lots. Salt Lake City permits internal, attached, and detached ADUs. Owner occupancy required. Maximum 50% of main home or 650 sq ft.
Provo
ADUs permitted per state law. Provo allows internal ADUs in most residential zones. Detached ADUs more restricted.
Ogden
ADUs allowed in residential zones. Ogden adopted ADU provisions in compliance with state law.
How Utah Compares to Other States
Below is a comparison of Utah with five states that have similar ADU-friendliness scores. This comparison helps illustrate where Utah stands nationally.
| State | Score | Statewide Law | Parking Req? | Owner Occ? | Ease |
|---|---|---|---|---|---|
| Utah (UT) | 50 | Yes | Yes | Yes | Moderate |
| Alaska (AK) | 45 | No | Yes | No | Moderate |
| New Hampshire (NH) | 55 | Yes | Yes | Yes | Moderate |
| New Mexico (NM) | 55 | No | No | No | Moderate |
| Rhode Island (RI) | 63 | Yes | No | Yes | Moderate |
| New Jersey (NJ) | 66 | Yes | No | Yes | Moderate |
Frequently Asked Questions About ADUs in Utah
Can I build an ADU in Utah?
Yes, ADUs are allowed in Utah. Utah has a statewide ADU law that requires local jurisdictions to permit ADUs on residential lots. This means your city cannot outright ban ADUs. The ease of building is rated "Moderate" with a friendliness score of 50/100.
Do I need to live on the property to have an ADU in Utah?
Yes, Utah generally requires owner occupancy — the property owner must live either in the main house or the ADU. This means you cannot rent out both units simultaneously.
How big can an ADU be in Utah?
Utah does not set a statewide maximum ADU size — this is determined by your local jurisdiction. Common local limits range from 600 to 1,200 square feet. Check your city's zoning code for the specific maximum.
Do I need extra parking for an ADU in Utah?
Utah may require additional off-street parking for ADUs. The specific number of spaces depends on your local jurisdiction. This can be a significant barrier if your lot has limited space for parking.
Can I rent out my ADU in Utah?
Yes, long-term rentals of ADUs are allowed in Utah. Short-term rentals (like Airbnb) are also generally permitted, though your city may have separate short-term rental regulations.
How long does it take to get an ADU permit in Utah?
The permitting timeline in Utah is: Varies by municipality. The statewide law sets maximum review periods that cities must comply with. Actual timelines can be affected by plan review backlogs, inspection scheduling, and the complexity of your project. Pre-approved ADU plans, where available, can significantly speed up the process.
Check ADU Rules for Your City
Use our ADU regulations lookup tool to find the specific rules for your city in Utah, or browse all 50 states to compare ADU regulations across the country. Remember that local rules may be more specific than state-level regulations.