ADU rules in Orem

Since Ordinance O-2026-0025 (adopted September 22, 2026), detached accessory dwelling units are a permitted use: they "shall be allowed only on properties where a single-family dwelling is permitted by zoning, and which are a minimum of eleven thousand (11,000) square feet in area" and "shall not be allowed in Planned Residential Development (PRD) Zones" (§22-6-11(D)). Existing accessory structures such as detached garages may be converted if the location, setback, size, parking, and height rules are met. The use table as amended by O-2026-0027 (October 13, 2026) also marks accessory dwelling units "N" in the R5 and OS5/ROS zones, and several planned-development zones and the Affordable Senior Housing overlay prohibit them. This implements Utah Code 10-21-304 (in force October 1, 2026), which requires cities like Orem to permit a detached unit on any lot of 11,000 square feet or more containing a single-family dwelling. Only one accessory dwelling unit of any kind is allowed per lot.

Interior accessory dwelling units are a permitted use but "shall be allowed only in owner-occupied detached single-family dwellings and in such other dwellings as may be specifically designated by ordinance but shall not be allowed in any R5 zone or PRD zone" (§22-6-11(C)). The unit "must be located within the footprint of the primary dwelling"; space connected only by a breezeway or similar structure does not count. Several planned-development zones (for example PD-17, PD-19, PD-20, PD-43) and the Affordable Senior Housing overlay also prohibit accessory dwelling units. A lot may have only one accessory dwelling unit of either kind.

For detached units, "For properties with an area of between 11,000 and 15,999 square feet the maximum size allowed for a detached accessory dwelling unit is 850 square feet", rising to 1,200 square feet on lots of 16,000 to 19,999 square feet and 1,500 square feet on lots of 20,000 square feet or more, with a 200 square foot minimum; "In no case shall the detached accessory dwelling have an area greater than 50% of the footprint of the primary dwelling on the property" (§22-6-11(D)(2)). Detached units are limited to a single story no taller than the house. Interior units have no floor-area limit; the practical constraint is that they must fit within the footprint of the house (§22-6-11(C)(2)), consistent with Utah Code 10-21-303, which bars cities from capping internal unit size relative to the primary dwelling.

For interior units, "The owner of the property must reside in either the primary or the accessory dwelling" (§22-6-11(C)(1)), and for detached units "The property owner of record is required to occupy either the primary dwelling or the detached accessory dwelling unit as a residence" (§22-6-11(D)(1)). A property counts as owner-occupied only if the owner lists it as primary residence on property taxes, state and federal tax returns, and driver's license or equivalent; the ownership definition requires a human owner of record with at least 50 percent equity, with trust and LLC rules (§22-6-11(B)(5)-(6)). The only waiver is a bona fide temporary absence of three years or less for a temporary job assignment, sabbatical, or voluntary service (§22-6-11(C)(1)(a)). Utah Code 10-21-304(4)(c) allows this requirement for detached units.

An interior unit needs "at least one (1) additional on-site parking stall", at least 8 by 16 feet (§22-6-11(C)(3)). For a detached unit, "One (1) additional parking space shall be provided for a detached accessory dwelling unit between 200 and 650 square feet in area" and "Two (2) additional parking spaces" for one larger than 650 square feet, on top of two dedicated spaces verified for the house (§22-6-11(D)(6)). Garage or carport spaces count toward the added stall only if the garage holds more than two spaces, and the driveway leading to the garage does not count unless it is widened beyond normal access without blocking the garage. Added stalls may not sit in the front yard setback, must be paved with concrete, masonry, or concrete pavers, and for detached units may not extend behind the unit's wall most nearly parallel to the front of the house. These figures match the caps in Utah Code 10-21-304(3)(b)-(c) and 10-21-303(3)(c).

"Accessory dwelling units shall be a permitted use on properties where zoning allows single-family detached residential dwellings, subject to the regulations of this article" (§22-6-11(A)). An interior unit needs an accessory dwelling unit permit and a detached unit needs a detached accessory dwelling unit permit from the Community Development Department, issued after the applicant submits a scaled site plan and floor plans and pays fees; no public hearing or discretionary approval is specified. A detached application must also show adequate utility access and capacity. Utah Code 10-21-304(3)(a) bars a conditional use permit for detached units in primarily residential zones.

Both interior and detached units "are subject to the rental dwelling license requirements set forth in Article 12-9 of the Orem City Code" (§22-6-11(C)(8), (D)(10)); a rental dwelling there means one rented for one month or longer. For a house with a legal accessory dwelling unit the license fee is paid with the initial application only, not annually, and a new owner must apply for a new license (§12-9-6). No license is needed when the owner occupies the home and rents only to listed relatives (§12-9-3). "Nothing herein shall be construed to allow more than one family to occupy either a single-family dwelling or an accessory dwelling unit" (§22-6-11(A)). The code has no short-term rental provision as of October 2026; the City Council was drafting an owner-occupied short-term rental ordinance in its September and October 2026 work sessions.