Orem planning staff lays out draft rules for detached accessory dwelling units ahead of state deadline

Planning staff presented a draft set of rules on July 1 for detached accessory dwelling units (DADUs) intended to meet a state requirement that the city adopt enabling regulations by Oct. 1.

The staff presentation said the city must allow DADUs on lots that contain a single‑family dwelling and are at least 11,000 square feet, the smallest lot size the state permits. The presenter summarized what the city can and cannot require under state law, including that DADUs must be allowed as permitted uses (not via conditional use permits) and that local design rules cannot conflict with state provision 102618.

Staff proposed allowing conversion of legally constructed accessory structures (for example, garages) to DADUs if they meet building, fire and setback standards. The draft would generally prohibit separate utility meters for DADUs to discourage dual‑rental schemes and would require an assessment of utility access and capacity before approval. Staff said units must meet normal occupancy standards (cooking and bathroom facilities) and pass building and fire inspections.

On size and form, staff described minimum and maximum guidance rather than fixed limits: a 200‑sq. ft minimum to avoid micro‑units, a statutory floor of 650 sq. ft that the city must allow, and suggested typical baselines of 850–1,000 sq. ft for 11,000‑sq. ft lots and up to about 1,200 sq. ft on large parcels. To preserve the accessory nature of DADUs, staff proposed a cap at about 50% of the primary dwelling’s size. The draft would limit DADUs to one story (20 ft maximum for pitched roofs; 14 ft for flat roofs) while allowing interior loft space limited to no more than 20% of total floor area.

Setbacks and siting proposals included a 10‑ft minimum from property lines (creating roughly 20 ft separation between adjacent dwellings if both have 10‑ft side setbacks) and a 25‑ft setback for double‑frontage lots so ADUs do not sit near a street. Staff noted the option to prohibit DADUs from front yards or between a dwelling and the street.

On parking, staff said state law limits local requirements: the draft would require one off‑street dedicated parking space for units 650 sq. ft or smaller and two dedicated spaces for larger units, with replacement parking required if a garage is converted. Staff emphasized the need to show dedicated off‑street stalls on site plans and said the city could require parking to be located behind the primary dwelling rather than in the front setback.

The presenter acknowledged unresolved details — for example, whether to require matching building materials to the primary dwelling — and said some issues will return to the commission after drafting. Staff announced a public hearing notice will be issued for July 15 and that formal draft language will be circulated for review and refinement ahead of the Oct. 1 state deadline.