ADU rules in Pleasant Grove

An accessory apartment may sit in a detached accessory structure associated with a single-family dwelling, including a tiny home on a permanent site-built foundation, but only in the A-1, R-R, R-1, RM-7, DV and Grove mixed housing zones, only on an owner-occupied single-family lot, and only where the lot can supply the required off-street parking. The city sets no minimum lot size for one, and in the R-1 zone a detached accessory structure may not exceed the height of the house or 25 feet, whichever is more restrictive. Utah Code 10-21-304, in force since October 1, 2026, requires a specified municipality such as Pleasant Grove to permit a detached accessory dwelling unit on any lot of 11,000 square feet or larger holding a single-family dwelling where single-family is a permitted use, without a conditional use permit in a primarily residential zone. Pleasant Grove's existing rule already allows detached units on smaller lots too; its only alignment change so far is the parking rewrite in Ordinance 2026-030 (adopted October 6, 2026).

A unit within or attached to a single-family residential building (over the garage, in the basement, or in an addition) is allowed in the A-1, R-R, R-1, RM-7, DV and Grove mixed housing zones; no accessory apartment may be in any multi-family dwelling, and the lot must satisfy the parking requirement. Utah Code 10-21-303(1)(a) independently makes an internal accessory dwelling unit a permitted use in any area zoned primarily for residential use, and Pleasant Grove's zone list covers every primarily residential district, so the two rules line up. Whether a structure counts as attached is now set by the section 10-6-2 definition of "Building, Attached" as rewritten by Ordinance 2026-015 (April 14, 2026) and now in the published code: "A structure physically joined to another structure or building by a common wall or floor to ceiling assembly to become one (1) continuous structure or building, not including breezeways greater than six feet (6') in length." A separate building merely sitting within six feet of the house no longer counts as attached, so it is held to the accessory-structure rules.

Section 10-15-47 sets no floor-area limit for an accessory apartment. It limits occupancy instead (one person, a related family, or up to four related and unrelated persons living as a single housekeeping unit) and requires the unit to meet the zoning requirements that apply to properties in a single-family neighborhood. No section of Chapter 15 sets an accessory-building size limit; 10-15-37 covers second kitchens, a separate topic. What does bind is height and bulk in the zone standards: in R-1 an accessory structure may not exceed the height of the dwelling or 25 feet, whichever is more restrictive, and a tiny home must be at least 192 square feet under the section 10-6-2 definition. Size does now matter for parking: a detached unit over 650 square feet needs two added spaces instead of one. For a unit built inside the house, Utah Code 10-21-303(1)(b)(i) bars the city from regulating its size in relation to the primary dwelling, and Utah Code 10-21-304(4)(b)(i) lets the city keep a detached unit from being larger than the house, a limit Pleasant Grove has not adopted.

No accessory apartment may be created, established, or occupied unless the property owner occupies either a portion of the main dwelling or a detached accessory unit on the same lot. The section defines owner occupancy in detail (primary dwelling and mailing address, a named human owner of record, at least 50% recorded equity interest, special rules for trusts and limited liability companies, and a documentary burden on the claimed owner) and exempts only a bona fide temporary absence of three years or less for a job assignment, sabbatical, or voluntary service. State law backs the requirement: Utah Code 10-21-303(3)(j) lets a municipality bar the rental of an internal accessory dwelling unit that is not in the owner's primary residence, and Utah Code 10-21-304(4)(c), in force since October 1, 2026, lets it require the owner to live in the house or the detached unit.

Ordinance 2026-030, adopted October 6, 2026 and effective on passage and posting but not yet in the published code, struck the old six-space rule in section 10-15-47(J). Now: "If four (4) off-street parking spaces are provided for the primary dwelling unit, no additional parking spaces will be required for internal accessory apartments," and a house without four spaces must add one; for detached units, "One (1) additional off-street parking space shall be provided for detached accessory apartments that have a maximum square footage of six hundred fifty (650) square feet" and two above 650 square feet. The house itself still needs four spaces under section 10-18-3 (two in a garage or carport plus two in the driveway), and a garage converted to living space must be replaced by a new garage or carport before occupancy. Spaces may not sit in a front or street-side setback except in an approved driveway, tandem driveway parking counts up to two spaces, and surfaces must be paved, with limited alternatives for accessory-unit spaces not connected to the street. The new text speaks only to internal and detached units, so ask Community Development how a unit in an addition outside the house's footprint is counted.

Accessory apartments (use 1124) are listed as a permitted principal use in the A-1, R-R, R-1 and RM-7 zones, and approval runs through registration with the Community Development Department: a $25 fee with a registration form, site plan, and floor plans, plus a building permit for any construction, corrections identified by the chief building official, and photos of life-safety items. It is a staff-level process with no hearing described. An unregistered apartment is not legal or approved, and failure to register can bring a $500 fine that may become a lien on the property. Utah Code 10-21-304(3)(a), in force since October 1, 2026, separately bars the city from requiring a conditional use permit for a detached accessory dwelling unit in a primarily residential zone, which matches the city's existing practice.

The accessory apartment shall not be intended for sale or detached by deed and shall only be rented. Occupants are limited to one person living alone, two or more persons related by blood, marriage, adoption, legal guardianship, or foster care, or up to four related and unrelated persons living as a single housekeeping unit, plus a temporary guest staying under 30 days in any rolling year. The city sets no minimum lease term and, in its 2024 moderate income housing report, told the state it does not require a business license to rent an accessory dwelling unit. State law leaves room for stricter rules the city has not adopted: Utah Code 10-21-303(3)(i) lets a municipality bar rentals of an internal unit shorter than 30 consecutive days, and Utah Code 10-21-304(4)(b)(iv), in force since October 1, 2026, lets it bar rentals of a detached unit shorter than 90 consecutive days.