Sandy planning staff lays out proposed ADU ordinance required by state law

Planning staff presented a detailed draft ordinance to allow detached accessory dwelling units (ADUs) and to clarify extended living areas, explaining the changes are driven by state law (SB 284) that takes effect Oct. 1. The presentation defined ADUs as self‑contained rental units with kitchen, bathroom and sleeping areas, and distinguished them from extended living areas intended for non‑rental family use.

Staff recommended the city initially adopt the state‑mandated minimum — detached ADUs on residential lots 11,000 square feet or larger — and consider expanding eligible areas in a later code update. The draft ties ADU maximum size to the primary dwelling (no larger than 75% of the primary dwelling footprint) and to accessory‑structure building coverage tables so footprint, not total floor area, drives allowed size.

On parking, staff recommended following state allowances: one additional off‑street parking space for detached ADUs of 650 square feet or less, with reduced or no additional parking required within 0.5 mile of a transit station. Staff also proposed owner‑occupancy affidavits and a special‑use permit with a business license for rented ADUs to enable tracking and enforcement.

The planner summarized the intent: “The state has mandated that cities such as Sandy must allow detached ADUs,” and staff said they favored a cautious, implementable approach rather than immediately broad changes. Staff will return a revised draft that incorporates commission feedback before the Aug. 20 hearing.