Salt Lake City, UT Accessory Structures: ADU Permits (2026)

Salt Lake City overhauled its ADU regulations in late 2018 and again expanded permissiveness following Utah's HB 82 (2021), codified at Utah Code 10-9a-530, which forced municipalities to permit internal accessory dwelling units by right in single-family residential zones. Under SLC Code 21A.40.200, a single ADU is permitted on any lot with a single-family dwelling in zoning districts listed in Chapter 21A.33. The permit pathway is administered through Salt Lake City Building Services using the Accela permit portal (aca-prod.accela.com/SLCREF). All ADUs (internal conversions of basements/garages, attached additions, and detached structures) require a building permit; attached and detached units also require electrical, plumbing, and mechanical permits. Detached ADUs are capped at 17 feet in height, increasable to 24 feet (pitched roof) or 20 feet (flat roof) with one foot of added side/rear setback for every foot above 17 feet. To accelerate adoption, the city published a set of pre-approved Standard Plans through Building Services that homeowners may use, though a site review and all standard plan-review fees still apply. Plan review typically runs about six weeks. Internal ADUs may not be regulated more strictly than the primary dwelling per state preemption.