Thinking about a basement apartment or a backyard cottage in Riverton? You are not alone. Many owners want extra space or steady rental income, but the rules can feel confusing. This guide walks you through permits, owner‑occupancy, parking, design basics, utilities, and costs so you can plan with confidence. Let’s dive in.
ADU basics in Riverton
Riverton allows one accessory dwelling unit on a single‑family lot. You can create an ADU inside your home, convert an existing detached structure, or build a new detached accessory building. ADUs do not count as a separate unit of density and cannot be sold apart from the main lot. Review the city’s accessory dwelling rules in the Riverton municipal code to confirm eligibility and standards. Riverton’s ADU code outlines the local rules.
Utah law also protects internal ADUs in owner‑occupied homes. An internal ADU is inside the existing footprint of a single‑family dwelling and is intended for rentals of 30 days or more. Cities can set certain limits, but they must follow the state framework. You can read the state definition and allowed city controls in Utah Code Section 10‑9a‑530.
Permits and registration
Riverton requires you to register the ADU with the planning department and obtain all building permits before construction or conversion. Inspections are required, and the ADU cannot be occupied until the city issues a certificate of occupancy or ADU permit. The city charges a $175 ADU registration processing fee, and building permit fees are separate. Each new owner must renew the ADU registration if they want to keep it permitted. See Riverton’s registration, inspection, and fee requirements.
Owner‑occupancy rules
Riverton requires an owner occupant to live on the property in either the main home or the ADU. The code allows limited exceptions for bona fide temporary absences, such as military service, a temporary job assignment, a sabbatical up to three years, or if the owner is in a hospital or nursing facility. You must provide an owner‑occupancy statement during registration. Noncompliance can result in revocation of the ADU permit. Review the owner‑occupancy language in the city code.
Parking and access
Riverton requires a minimum of one dedicated on‑site parking space for an ADU. A driveway space can count if it is at least 20 feet deep by 8 feet wide between the property line and the off‑street parking area, and if the main home’s parking still meets code. ADU entrances inside an existing home must use existing doors or be placed to keep a single‑family look, often at the rear or on a corner side. Detached ADU entrances should face an alley, a public street, or the rear of the main home, and exterior stairs must meet separation rules. Parking and entrance standards appear in the ADU section.
Design and size basics
Detached ADUs must meet accessory structure setbacks, typically at least 5 feet from side and rear property lines. Keep at least 10 feet between the accessory building and the main dwelling, and do not locate accessory structures in required front yards. Maximum accessory structure height is generally 20 feet, with up to 25 feet on larger parcels, and total accessory building area counts toward the lot’s accessory coverage limits. For larger structures, exterior materials must match or be consistent with the main home, and second‑story or rooftop decks on ADUs are not allowed. Riverton’s code details setbacks, height, materials, and deck limits.
Utilities and impact fees
Utah law lets cities prohibit separate utility meters for internal ADUs. Confirm the metering policy with Riverton and your utility provider early, since separate meters, if allowed, can require trenching and meter upgrades. For internal ADUs built within an existing home, state law prohibits impact fees, which can lower your cost to create an IADU. Check with Riverton to see how detached ADUs are treated. Read the state rules on IADUs and municipal authority and the 2023 update on impact fees for internal ADUs.
Short‑term rentals and occupancy
State law defines internal ADUs for rentals of 30 days or more, and cities may prohibit shorter stays. Riverton also ties occupancy to the city’s definition of a family and enforces occupancy limits. If you are considering nightly or weekly rentals, confirm the city’s short‑term rental rules and any licensing first. For the state’s IADU rental definition, see Utah Code Section 10‑9a‑530.
Costs, taxes, and insurance
Expect the ADU registration fee and separate building permit fees. Internal ADUs in existing homes are not subject to impact fees under state law. New construction or conversions that add value often increase your property’s assessed value once complete, which can change your taxes. For general assessor practice, review this example guidance and contact the Salt Lake County Assessor for local procedures. Example assessor overview on ADUs and assessment. Also talk with your insurer about coverage for rental use and any needed endorsements.
HOAs and private covenants
Homeowners’ associations often regulate exterior changes, detached structures, and rentals. Utah law places limits on how far an HOA can restrict internal ADUs for long‑term rental in owner‑occupied detached homes, but the details are fact specific. Review your CC&Rs and speak with your HOA board or counsel early. A helpful primer on association rules is available here: Overview of Utah HOA rules and limits.
Quick project checklist
- Verify your zoning and confirm you are in a single‑family zone that allows one ADU per lot.
- Read Riverton’s ADU section and note the $175 registration fee and separate building permit fees.
- Set a parking plan that provides at least one on‑site space for the ADU.
- Meet with Riverton Planning and Building to confirm entrances, setbacks, utilities, and the inspection timeline.
- Hire a designer familiar with ADU code needs like egress, ceiling heights, ventilation, and plumbing.
- Decide on utility metering early and confirm what the city and utility will allow.
- Submit your ADU registration with owner‑occupancy documentation, apply for building permits, and schedule inspections. Do not occupy until you receive a certificate of occupancy.
- Check with your lender, the Salt Lake County Assessor, and your insurance carrier about impacts to your loan, taxes, and coverage.
Ready to map out your ADU strategy or find a Riverton home with ADU potential? Let’s talk about value, resale, and rental demand so you can move forward with clarity. Reach out to Nick Booth Real Estate for local guidance and a smooth process.
FAQs
Can I add a basement apartment in Riverton?
- Yes. Internal ADUs inside the existing footprint are allowed under state law and permitted locally, subject to building and fire codes, owner‑occupancy, and city registration.
Do I have to live on the property to keep an ADU?
- Yes. Riverton requires an owner occupant in either the main home or the ADU, with limited exceptions for temporary absences and certain medical situations.
How many parking spaces does an ADU need in Riverton?
- At least one dedicated on‑site space is required, and a driveway space at least 20 feet by 8 feet can count if the main home’s parking still meets code.
Are internal ADUs exempt from impact fees?
- Yes. Utah’s 2023 updates prohibit impact fees for internal ADUs built within an existing home; detached ADUs can be treated differently.
Can I do short‑term rentals in an ADU?
- Internal ADUs are defined for long‑term rental of 30 days or more, and cities may prohibit rentals under 30 days, so confirm Riverton’s rules before planning nightly stays.
Can my HOA block my ADU?
- HOAs often regulate exterior work, but Utah law limits some restrictions on internal ADUs in owner‑occupied detached homes; review your CC&Rs and consult the board early.
