Multigenerational Living and ADUs in Utah Valley

Living September 30, 2026 7 min read ✓ Updated September 30, 2026

JoAnn Giordano Editor-in-Chief, Provo.com How we make Provo.com

Utah has a long tradition of families living close, and many Utah Valley houses show it, with basements that have room for a second kitchen, a side door and bedrooms that could become an apartment. Today the reasons vary, from aging parents who need help nearby and adult children saving for a house to newlyweds, returning missionaries and the plain cost of housing. Utah law made the basement apartment easier in 2021. This guide covers what the law allows, what your city may still require, and the family questions no law answers.

The 2021 law: internal ADUs

Since October 1, 2021, Utah law has treated an internal accessory dwelling unit, an apartment created within a detached single-family home's footprint, as a permitted use in areas zoned primarily residential. Under the law:

Cities may require: a permit or business license, that the owner live in the house, one additional off-street parking space, no change to the home's exterior appearance, and a single utility meter. They may also prohibit internal ADUs on lots of 6,000 square feet or less, and in mobile homes.
Cities may not regulate: the unit's size relative to the house, or the lot's size or frontage beyond the 6,000-square-foot threshold.
Homeowners associations: may not prohibit them.
Rentals: the unit is defined for stays of 30 consecutive days or longer, and cities may bar short-term rentals.

The college-town exception

A city may prohibit internal ADUs in up to 25 percent of its residentially zoned area, or up to 67 percent if a university with 10,000 or more students is in the city. Provo and Orem, home to BYU and UVU, fall in that second group, so whether a basement apartment is allowed can depend on your exact zone. Check with the city before you plan the remodel; for Provo, see Provo Zoning, Explained, which walks through the city's conditions.

Detached ADUs

A backyard cottage or garage apartment is a separate legal regime from an internal unit, with its own rules; see Detached ADUs in Utah Valley.

The family questions no law answers

Privacy: a separate entrance and kitchen make the arrangement last.
Money: agree in writing whether a family member pays rent, shares utilities or contributes to the mortgage.
Aging in place: for parents, a ground-level bedroom and bathroom may matter more than a basement.
The exit plan: what happens if a parent needs more care, or an adult child moves out.

For parents who would rather live near family than with it, see 55-Plus Active Adult Communities in Utah Valley.

Before you remodel

Confirm the zone allows an internal ADU at your address.
Pull the permit. Egress windows and fire separation matter for safety.
Check your insurance once someone else lives in the unit.
Talk to your lender if you are counting on rent to qualify for a loan.

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Frequently Asked Questions

Can I add a basement apartment to my house in Utah?

In most residential areas, yes. Since October 1, 2021, Utah law has made an internal accessory dwelling unit, an apartment created inside a detached single-family home's existing footprint, a permitted use in areas zoned primarily residential. Cities may still require a permit, owner occupancy, an extra parking space and no change to the home's exterior, and may prohibit them on lots of 6,000 square feet or less.

Can a city ban internal ADUs?

Only in part of the city. A city may prohibit them in up to 25 percent of its residentially zoned area, or up to 67 percent in a city with a university of 10,000 or more students, which describes Provo and Orem. Homeowners associations may not prohibit them.

Can I rent the apartment on Airbnb?

Not under the state law's terms. An internal ADU is defined for rentals of 30 consecutive days or longer, and cities may bar short-term rentals in them.

What about a separate cottage in the backyard?

Detached ADUs are a separate legal regime from internal ones, with their own rules; see our detached ADU guide.

When did Utah's internal ADU law take effect?

October 1, 2021.

Are basement apartments allowed in Provo and Orem?

It depends on the zone. Cities with a university of 10,000 or more students may prohibit internal ADUs in up to 67 percent of their residential area, and Provo and Orem fall in that group, so check your exact address with the city.

What should families agree on before sharing a house?

In writing, whether a family member pays rent, shares utilities or contributes to the mortgage, and how privacy will work, since a separate entrance and kitchen help the arrangement last.

Do I need a permit to finish a basement apartment?

Yes. Pull the permit, because egress windows and fire separation matter for safety, and check your insurance once someone else lives in the unit.

JoAnn Giordano

Editor-in-Chief

JoAnn Giordano is the editor-in-chief of Provo.com. Having lived in and around Utah Valley for years, she leads the site's editorial direction with a focus on the comprehensive, honest local coverage that helps residents, students, and newcomers feel at home. When she's not shaping Provo.com's restaurant and neighborhood coverage, she's exploring the valley's trails and tracking down the best new spots on Center Street.

Multigenerational Living in Utah Valley: The ADU Law, the Basement Apartment and Moving the Parents In