This site is an evaluation tool for homeowners and residents in Utah and nearby Wasatch Front communities. It answers two separate questions: can you create an internal accessory dwelling unit inside the existing house, and can you build a detached unit in the yard.
Utah’s 2021 internal-ADU law (originally H.B. 82) makes one internal accessory dwelling unit a permitted use inside an owner-occupied detached single-family home in a residential zone. The unit has to stay within the home’s footprint and is meant for rentals of 30 consecutive days or longer.
Cities may still require owner occupancy, one extra parking space, and a permit. They may also prohibit an internal ADU on properties of 6,000 square feet or less. This map flags those smaller properties as “needs a closer look” instead of a yes.
S.B. 284 requires a specified municipality to allow one detached ADU as a permitted use on a property of 11,000 square feet or larger that contains a permitted single-family dwelling. The detached-ADU section becomes operative on October 1, 2026. Cities then have to bring local ordinances into line.
A specified municipality is a first- through fourth-class city, or a fifth-class city of 5,000 or more people in a first-, second-, or third-class county. Almost every larger Utah County and Wasatch Front city meets that test. Towns and some small cities do not.
Cities may still require owner occupancy, setbacks, height and design rules, and may ban rentals shorter than 90 days. They cannot require a conditional-use hearing in a primarily residential zone for a qualifying property, and parking is capped.
Properties under 11,000 square feet are not covered by the statewide floor. A city may still allow a backyard unit there — we mark those gold or amber, not green.
Addresses come from the Utah Geospatial Resource Center address-point layer. Property size, assessor class, and parcel outlines come from county Land Information Record parcels. City names and populations come from UGRC municipal boundaries.
The first release colors parcels in Salt Lake, Utah, Davis, Weber, Tooele, Summit, Wasatch, and Morgan counties. Address search will also try those counties if a point falls near a county line.
Treat a green property as “worth talking to planning,” not as permission to build. When you are ready for next steps, use the Before you build checklist. Orem, Provo, Salt Lake City, Lehi, and Sandy also show curated local planning notes on the property summary.