Utah Accessory Dwelling Unit and Basement Apartment Rules

An internal accessory dwelling unit is a separate dwelling unit created within a primary dwelling. It typically includes independent living, sleeping, cooking, and sanitation facilities. A finished basement with a bedroom and wet bar is not necessarily an approved ADU. Legal status depends on use, configuration, permits, and local requirements.

State law limits how municipalities and counties may restrict internal ADUs, but local governments retain authority over building safety and several operational requirements. Cities may require registration, owner occupancy, parking, separate entrances, address identification, or proof that the property is not used as a short-term rental. Because rules change, verify the current ordinance for the specific city and zoning district.

• Ask for the original permit and certificate or approval.
• Confirm zoning and current registration.
• Verify owner-occupancy requirements.
• Review parking and entrance compliance.
• Check egress, fire separation, smoke and carbon-monoxide protection.
• Confirm electrical, plumbing, heating, and kitchen permits.
• Review the existing lease and security deposit.
• Confirm whether utilities are shared or separately metered.

Projected ADU income may help a buyer, but lenders vary in how they count rent. Legal status, appraiser treatment, lease history, and loan program rules matter. Do not base affordability on full rent without budgeting vacancy, utilities, maintenance, turnover, insurance, taxes, and the possibility that the unit cannot be rented as planned.

Permission for an internal ADU does not automatically authorize nightly or short-term rental use. Local ordinances, business licenses, owner occupancy, HOA restrictions, and zoning can prohibit or limit short stays.

Before construction, obtain a zoning review and permit path. The cost may include egress windows, fire separation, electrical upgrades, heating changes, parking work, utility modifications, design fees, and impact-related requirements. A cheap unpermitted conversion can become expensive when the owner sells, refinances, insures the property, or responds to a complaint.

An ADU can improve affordability and property flexibility, but only if the unit is legally usable and financially realistic. Verify the local approval, physical code compliance, rental restrictions, and operating costs before paying an income-property premium.