Orem, UT Accessory Structures: ADU Rules (2026)

Orem City defines an accessory apartment as a subordinate dwelling with its own eating, sleeping, and sanitation facilities within a main residential building, and the City's ordinance requires that the owner of the property live in either the main residential building or the accessory apartment. Orem City Code Section 22-6-8(D)(7) further provides that a detached accessory building/structure in a residential zone shall not be designed or used as a guest house or a separate apartment unit, so a second dwelling unit generally must be internal to the main home rather than a freestanding building. Utah state law preempts much of the internal-ADU question: under Utah Code Section 10-9a-530 (renumbered 11/6/2025, formerly 10-9a-511.5), in any area zoned primarily for residential use the use of an 'internal accessory dwelling unit' (an ADU created within, and within the footprint of, a detached single-family primary dwelling occupied as the owner's primary residence, for long-term rentals of 30 consecutive days or longer) is a permitted use, and a municipality may not impose restrictions on the unit's size relative to the primary dwelling, total lot size, street frontage, or internal connectivity. Cities like Orem retain authority under Subsection (4) to require an owner permit/license, one additional on-site parking space (unless four off-street spaces are already required), replacement of garage/carport parking converted to habitable space, and to prohibit the rental if the dwelling is not the owner's primary residence or if the lot is 6,000 square feet or less in size.