Davis County · about 33,000

Kaysville

Detached permitted on 11,000 sf lots

Ordinance 26-09-04, adopted and signed September 17, 2026, replaced the internal-only rule. A detached unit is now a permitted use on a lot of 11,000 square feet or larger that already has a detached single-family house. One ADU per lot — internal or detached, not both. The city’s older webpage still says a backyard cottage is not allowed. Use the ordinance.

Internal ADU: Permitted on a lot larger than 6,000 square feet, inside a legal single-family house. The house must still read as one dwelling. One off-street stall. Not rented for fewer than 30 consecutive days.
Detached ADU: Permitted on a lot of 11,000 square feet or larger with a detached single-family house that is itself a permitted use. Not in the front yard. A legally built accessory structure on a qualifying lot may be converted, if it meets the same standards and the building code. Kohottaa’s work is a new detached building.
Lot: Detached: 11,000 square feet or larger. Internal: larger than 6,000 square feet. Not on a property with a failing septic tank.
Size: Not larger than 50% of the footprint of the primary dwelling, including its garage, or 1,200 square feet, whichever is smaller. A two-story unit with a garage on the first floor is measured by the living area, not the garage. Height is the house or 25 feet to the peak, whichever is less.
Parking: One paved stall if the detached unit is 650 square feet or smaller; two if it is larger. Not tandem with the stalls required for the house. Asphalt or concrete. Replace any garage or carport stall the new building displaces.
Owner occupancy: The owner must live in the house or the ADU and file an occupancy affidavit. No more than one ADU on the lot. Same address, with “Unit B.” No separate utility meters.
Rental: A detached unit may not be rented for fewer than 90 consecutive days. An internal unit may not be rented for fewer than 30. A city rental permit and license are required before either is rented.
Design: Consistent with the house. Single-story setbacks match the primary dwelling. A two-story unit uses the zone’s rear-yard setback on the side as well. Recreational vehicles, trailers, and mobile homes are not a detached unit. A second-story deck is limited to an interior-facing wall.

Notes

The signed ordinance is 26-09-04, amending §17-31-3. The public notice is dated September 29, 2026. Municode had not caught up when we read it.

Confirm the zone is “primarily residential,” and confirm setbacks for that zone, before schematic design.

Statewide floor

Senate Bill 284, Utah Code §10-21-304, has been in effect since October 1, 2026. Every city on this list must allow a detached ADU as a permitted use — not a conditional use — on a lot of 11,000 square feet or larger that already has a permitted single-family house. A city may also allow one on a smaller lot. It may still set size, height, coverage, setbacks, and owner occupancy, and it may require that the unit not be larger than the house, not sit in the front yard, and not be rented for fewer than 90 days. Parking may not exceed one stall under 650 square feet, or two stalls at 650 square feet and above. A printed ban, or a conditional-use requirement, on a qualifying lot conflicts with the statute even if the code book is late. Confirm the city’s ordinance before anyone draws.

Inquire about a lot in Kaysville

We verify the ordinance that applies to your parcel as part of feasibility. Kaysville Planning