Utah Tiny Home Zoning Laws
Utah has moved faster on ADU legislation than almost any state in this series, with three separate bills building on each other in just five years — and the most recent one has an active compliance deadline you should know about right now.
A real, current deadline: Senate Bill 284, passed in 2026, expanded Utah's ADU rules to cover detached units (backyard cottages, garage apartments, standalone guest houses) for the first time — previously, many cities could prohibit these outright. Cities without an existing ADU policy must adopt one by October 2026.7 If you're researching a Utah city today, confirm whether it has already complied or is still working through this deadline.
1. The Legislative Stack
| Law | What It Did |
|---|---|
| SB 174 (2021) | Requires most municipalities to allow at least one internal ADU by right in owner-occupied single-family homes4,7 |
| SB 44 (2024) | Additional ADU reforms building on SB 1744 |
| SB 284 (2026) | Expands the mandate to detached ADUs statewide, with an October 2026 city compliance deadline7 |
2. Salt Lake City: The Most Developed Program
Salt Lake City has had a formal ADU ordinance since 2018 and added five pre-approved standard plans in 2023 specifically to cut design costs for homeowners.4 This kind of pre-approved plan library is a genuine time and cost saver, since it skips a significant chunk of the custom design review process. Salt Lake County has separately authorized development of tiny house villages specifically to combat homelessness.2
3. Other Cities and Counties
| Location | Notable Detail |
|---|---|
| Utah County | Maximum ADU size 1,200 sq ft; 4 ft side/rear setbacks; two-story ADUs allowed; 6 ft building separation6 |
| Provo, Orem & the Wasatch Front | Catching up to Salt Lake City's program under state preemption from SB 174 and SB 2844 |
| Beaver County | No clearly defined countywide ADU ordinance; depends heavily on how the county classifies accessory structures in your specific area5 |
| Emery, Grand & parts of San Juan County | Rural counties with lenient enforcement on unincorporated parcels4 |
4. Homes on Wheels
THOWs are classified as recreational vehicles under Utah law and cannot serve as a primary residence on a standard residential lot.4 Full-time THOW living is restricted to licensed RV parks, manufactured home communities, and rural unincorporated land where local zoning permits long-term RV occupancy.4
5. State Code Baseline
Utah enforces a single statewide construction code, the Utah State Construction Code (IRC with Utah amendments), administered by the Division of Occupational and Professional Licensing.6 Zoning, however, remains entirely local across the state's 29 counties.6
How to Verify Your Specific Situation
- Confirm your target city's current compliance status with SB 284's October 2026 deadline for detached ADU policies.
- If in Salt Lake City, ask about the pre-approved standard plans, since they can meaningfully reduce design costs and review time.
- If considering a home on wheels, confirm your target location allows long-term RV occupancy rather than assuming general ADU flexibility extends to THOWs.
- In rural counties like Beaver, confirm accessory structure classification directly with the county rather than assuming a standard ADU pathway exists.
Considering the ADU route? See how it compares nationally.
Read the National ADU Placement GuideSources
- Zook Cabins, "Tiny Home Regulations In Utah (2026 Guide)."
- Great Lakes Tiny Home, "What Counties in Utah Allow Tiny Houses."
- TinyHouse.com, "Tiny House Regulations in Utah (Complete Guide)."
- TinyHomeList, "Tiny Homes in Utah (UT)," updated April 2026.
- Zook Cabins, "ADU Regulations In Utah: The Complete Guide."
- Little Houses For Sale, "Tiny House Zoning in Utah."
- Cocoon, "Utah ADU Rules by City — 2026 SB284 Guide."