Zoning › State preemptions › Utah

Utah ADU By-Right in Residential Zones (SB 140 / HB 409) (UT)

Tracked preemption from the Utah overlay bundle.

Overview

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Effective
2023-05-03
Sunset
—
Authority
state
Scope
state:UT
Other Utah preemptions
Utah MIH Non-Compliance Enforcement PreemptionUtah First Home Investment Zone (HB 462)Utah SB 174 — Single-Family Housing Modifications (2022)Utah HB 82 — Internal ADU Mandate (2021)Utah Moderate Income Housing Plan (MIH) Framework

Trigger predicate

When this evaluates true for a parcel, the law's preempted fields take precedence over base zoning.

parcel.base_zone_category ∈ {res_sf, res_mf, mu}

Preempted fields

4 fields on the base district schema are rewritten when the trigger fires.

FieldOpValueNote
base_districts[category=res_sf].allowed_usesaddadu
base_districts[category=res_mf].allowed_usesaddadu
base_districts[category=mu].allowed_usesaddadu
review_typewaive_discretionary—ADU approval must be ministerial in residential and mixed-use zones

Citation

Authority source
Utah SB 140 (2023) + HB 409 (2023); Utah Code §10-9a-511.5
§ §10-9a-511.5 (internal + detached ADU by right in residential zones)
https://le.utah.gov/xcode/Title10/Chapter9A/10-9a-S511.5.html

Research notes

SB 140 (2023) and HB 409 (2023) together expanded Utah's ADU framework from HB 82 (2021) internal-only to include by-right detached ADUs in residential zones. Cities retain authority over size, height, and design standards consistent with the primary dwelling. Federal conflict check flagged because ADU build-out in base districts near Hill AFB (Layton, Clearfield, Roy) must reconcile with AICUZ noise/accident-potential zone restrictions.