State Preemption of Local Zoning in Utah
How Utah state law overrides local zoning ordinances. ADU preemption, lot split preemption, and impact on city-level regulations.
What Is State Preemption?
State preemption occurs when a state law overrides local government ordinances in a specific area. In land use, preemption means a city or county cannot adopt zoning rules that are more restrictive than the state standard. If a city tries to prohibit something the state law permits, the state law wins.
Utah actively uses preemption in housing law. The state has enacted legislation that prohibits local governments from blocking certain types of housing development — most notably accessory dwelling units (ADUs) and lot splits.
ADU Preemption
Utah Senate Bill 174 (SB 174)
This law preempts local ordinances — cities cannot impose rules stricter than the state ADU standard. Effective 2021-05-05.
What local governments cannot restrict:
- Requires all Utah municipalities to allow at least one internal ADU (within or attached to primary dwelling) by-right on all single-family lots
- Municipalities cannot require a conditional use permit or other discretionary approval for internal ADUs that comply with objective standards
- Municipalities cannot require owner-occupancy as a condition of internal ADU approval
- Sets statewide baseline — local municipalities may allow more types of ADUs (such as detached) beyond state minimum
How Preemption Affects Utah Cities
State preemption applies to every incorporated city and unincorporated area in Utah. Select a city below to see how state preemption interacts with local zoning rules.
Source: Utah Senate Bill 174 (SB 174). Last verified April 5, 2026. View source