ADU rules in Utah
Representative cities: Salt Lake City, Provo.
ADU permit rule
ConditionalGenerally allowedcity authority
Fee basis
Valuation-based; set by the city under the statewide code.
Typical timeline
Plan review through the city (SLC first review ~14 business days).
Setback
—
Area threshold
Local zoning sets size, setback, and parking limits; state law supports ADU by right in many cases.
Exempt if
None — an ADU always requires zoning approval and a building permit; construction must meet the amended IRC.
Go / no-go
allowed
Utah follows the statewide Utah Construction Code (IRC-based). ADU allowances are set by local zoning; construction must meet all IRC standards. Local jurisdictions cannot enforce rules more restrictive than the state code (Utah Code Title 15A).
🧮
Estimate build cost
Model this ADU's construction cost by type, size & finish.
📊
Model rental ROI
Turn the build cost into rent, payback & 20-year cash flow.
Frequently asked questions
Do I need a permit to build an ADU in Utah?
Per Utah rules, an ADU is "conditional" for a permit and the authority is "city". Utah follows the statewide Utah Construction Code (IRC-based). ADU allowances are set by local zoning; construction must meet all IRC standards. Local jurisdictions cannot enforce rules more restrictive than the state code (Utah Code Title 15A). Always confirm with the issuing building department.
How big can an ADU be in Utah?
Area threshold: Local zoning sets size, setback, and parking limits; state law supports ADU by right in many cases.
What are the ADU setbacks in Utah?
Setback rules vary by city in Utah; confirm with the local planning or building department.
How much does an ADU permit cost in Utah?
Fee basis: Valuation-based; set by the city under the statewide code.
State-wide sources: Salt Lake City — Building Permit Applications · Utah Division of Occupational and Professional Licensing (Uniform Building Code Commission) · Utah Code Title 15A, Chapter 3 — State Construction Code
Plan the ADU numbers for Utah
ADU build cost calculator
Estimate cost by type, floor area, state and finish level.
Rental ROI and payback
Model rent, cash flow and how long the build takes to pay for itself.
Financing comparison
HELOC vs construction loan vs home equity loan vs cash, on example rates.
Does your ADU need a permit?
Run the go / no-go checker with your own project details.