Key Facts Ordinance Text Full Breakdown Violations FAQ Sources More in Davis County

Davis County, UT Accessory Structures: ADU Rules (2026)

Some Restrictions

Compiled from the official code textEditor Martyn O'NeillLast verified July 2026

ADU rules in Davis County, UT, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.

Key Facts

Governing law: Utah Code §10-9a-530
Internal ADU: Permitted use in residential zones
Extra parking: Up to 1 space may be required
Owner-occupancy: Required to rent
Detached ADU: City or county zoning applies

ADU Eligibility Quick-Check

An Accessory Dwelling Unit (ADU) is a smaller, independent living unit on the same lot as a single-family home: converted garages, detached cottages, basement or attic conversions, and attached additions all qualify. Most states have streamlined ADU permitting since 2020, but local rules still control size, height, and setback.

Is your lot zoned single-family or multi-family residential?
Does your lot have at least 1,200 sq ft of buildable space?
Is your existing home owner-occupied (in most states this is not required, but some require it for ADU permits)?
Will the ADU stay under your state's size cap (commonly 850-1,200 sq ft for detached)?
Can you provide one off-street parking space (waived in many states within 0.5 mi of transit)?

If you answered 'yes' to most of these, you likely qualify in Utah under recent ADU streamlining laws. The Davis County, UT rules below cover local size, height, and setback requirements.

Summary

Utah law makes an internal accessory dwelling unit a permitted use in residential zones. Layton, Bountiful, and other Davis County cities must allow one internal ADU inside an owner-occupied single-family home; detached ADUs stay under local zoning.

These county ordinances apply to unincorporated areas of Davis County. Incorporated cities within the county may have their own rules that take precedence over county-level regulations.

the use of an internal accessory dwelling unit is a permitted use

View official code

Full Breakdown

Under Utah Code 10-9a-530, an internal accessory dwelling unit (created within the primary home's footprint for 30-day-plus rentals) is a permitted use in residentially zoned areas, and cities may not ban them. A municipality may require one additional on-site parking space and may prohibit renting the ADU if the home is not the owner's primary residence. Detached ADUs and units on unincorporated Davis County land follow Davis County or city zoning. Confirm specifics with your city (Layton Planning 801-336-3780) or Davis County Planning.

Violations & Fines

Renting a non-permitted or non-owner-occupied ADU can trigger zoning enforcement, fines, and property liens under the statute's remedies.

Frequently Asked Questions

Can Layton ban an internal ADU?

No. State law makes an internal ADU a permitted use in residential zones; the city may add only limited parking and owner-occupancy conditions.

Are ADUs allowed on unincorporated land?

Davis County zoning governs unincorporated lots; the state internal-ADU mandate applies to cities. Check Davis County Planning for your zone.

Sources & Official References

Other rules in Davis County

Parking Rules: Overnight ParkingSome Restrictions Parking Rules: Street Parking LimitsSome Restrictions Shed & Carport RulesSome Restrictions Garage ConversionsSome Restrictions Noise Ordinances: Barking DogsSome Restrictions Parking Rules: Driveway RulesSome Restrictions Animal Ordinances: Breed RestrictionsSignificant Restrictions Animal Ordinances: Pet LimitsSome Restrictions

All Davis County rules

How Davis County compares: Easiest Cities to Build an ADU·Compare Davis County to another location·View the Utah accessory structures overview

See something wrong?

Help us keep this page accurate. If you notice an error or outdated information, let us know.