ADU Laws in Utah (2026)
Utah state ADU law details, key provisions, preemption status, and recent legislative changes for accessory dwelling units.
Law Name
Effective Date
2021-05-05
Preempts Local Ordinances
Yes — state law overrides local restrictions
Has State Law
Yes
Statewide ADU Preemption Applies
State law establishes statewide preemption standards that supersede local regulations. The citation and source below confirm the verified legal basis.
Key Provisions
Requires all Utah municipalities to allow at least one internal ADU (within or attached to primary dwelling) by-right on all single-family lots · Source
Municipalities cannot require a conditional use permit or other discretionary approval for internal ADUs that comply with objective standards · Source
Municipalities cannot require owner-occupancy as a condition of internal ADU approval · Source
Sets statewide baseline — local municipalities may allow more types of ADUs (such as detached) beyond state minimum · Source
Applies to all municipalities regardless of population size · Source
Covers internal ADUs — attached or within the footprint of the primary dwelling · Source
Legislative History
Official Sources
What Does Preemption Mean for Local Cities?
Because Utah law preempts local ordinances, individual cities cannot impose restrictions stricter than the state standard. A city may still have additional administrative requirements, but cannot deny ADU applications that comply with state minimums.
Learn about Utahzoning preemption →Source: Utah Senate Bill 174 (SB 174). Last verified April 5, 2026. View source