Frequently Asked Questions
Utah ADU answers.
Does Utah have a statewide ADU law?
Yes, but through two separate laws. Utah Code § 10-9a-530 (HB 82, 2021) has given internal ADUs a statewide by-right guarantee for several years. Detached ADUs are newly covered by SB284 (2026), which requires cities of 5,000+ residents to permit them on 11,000+ sq ft lots by October 1, 2026. Local zoning, building, utility, site, and private-covenant requirements may still apply; verify the current rules for the property before design or construction.
Can my HOA block my Utah ADU?
For internal ADUs, no — where an internal ADU would not violate local zoning or building, health, or fire codes, state law says renting it may not be prohibited by any private community association CC&R or HOA rule. This is different from most other states, where HOA covenants are generally not preempted by ADU laws. Detached ADUs don't carry this same statewide HOA override.
Do I have to live on my property to rent an internal ADU in Utah?
HB 82 removed the statewide owner-occupancy mandate for internal ADUs, but it did not forbid cities from keeping their own owner-occupancy condition. Many Utah cities still require the owner to reside in the primary home or the ADU for at least six months per year — confirm with your specific city.
Can I rent my Utah internal ADU on Airbnb?
No. State law defines an Internal ADU specifically as a unit offered for long-term rental of 30 consecutive days or longer, which excludes short-term or nightly rentals by definition — not just by local ordinance.
What is the cheapest ADU to build in Utah?
An internal ADU — a basement or interior conversion within the existing home's footprint — is typically the cheapest and fastest-permitted option statewide, commonly $60,000–$140,000 depending on finish level.
Can I build a detached ADU anywhere in Utah?
Not automatically. Detached ADUs depend entirely on your city's ordinance. SB284 (2026) now requires cities with 5,000+ residents to permit them, generally on lots of 11,000+ sqft, with an October 2026 compliance deadline — but the precise contours vary city to city and continue to be revisited by the legislature.
Why does Sandy rent for more than Salt Lake City?
Sandy and other south-valley Salt Lake County suburbs consistently post higher average rents than Salt Lake City proper, often exceeding $1,700/month for a 1-bedroom — a genuine, sourced market condition tied to newer housing stock and suburban demand.
What is the ROI on an ADU in Utah?
The adopted Utah one-bedroom planning range is $1,125–$1,750 per month, derived from the HUD FY2026 revised FMR market basket under ROI-CM-1.4. Payback is calculated from the homeowner's budget, ADU type, size, rent range, and a 30% operating-expense reserve. Property value uses a 15% national planning input with a 10%–20% uncertainty range; it is not a valuation.
What can Utah cities not require for a detached ADU under SB284?
Covered cities cannot require a conditional-use permit for a compliant detached ADU. They also cannot demand more than two off-street parking spaces for a unit 650 sq ft or larger, or more than one space for a smaller unit, and cannot enforce design standards that conflict with Utah Code § 10-20-618. Local building, health, and fire codes still apply.
Has Utah's October 2026 detached ADU deadline already passed?
No — as of this review, SB284's compliance deadline of October 1, 2026 is still ahead. Covered cities (those of the first through fourth class, plus fifth-class cities with 5,000+ residents in the state's larger counties) must adopt a qualifying detached-ADU ordinance by that date. Confirm with your specific city whether it has already adopted its ordinance or is still finalizing it.
