River Heights planning commission debates external ADUs — definitions, size, billing and code placement

The River Heights Planning and Zoning Commission devoted a large portion of its Jan. 27 session to external accessory dwelling units (ADUs), weighing how — and whether — the city should permit freestanding dwelling units on private lots.

Noel, a city planning staff member, said the commission currently lacks explicit ADU policy in the general plan and code and proposed adding definitions and standards. Commissioners discussed key policy choices: whether ADUs must sit on permanent foundations (excluding tiny homes on wheels), maximum unit size (examples referenced a 1,000-square-foot cap used elsewhere), minimum lot-size thresholds (one commissioner suggested limiting permits to larger lots), parking requirements (several cities require two off-street paved spaces), and setbacks and fire-code compliance (members suggested increasing accessory-building side and rear setbacks from 3 to 5 feet and discussed 10–15 foot separations between structures).

Noel noted several practical constraints: ADUs typically must connect to the primary residence’s water and sewer to avoid separate service lines, and utility-billing arrangements vary — the draft described billing for the ADU combined with the primary meter but some sample codes require separate billing or addresses. Commissioners also discussed whether to create a new chapter under Title 10 (proposed Chapter 23) to make ADU rules easier to find and how to reconcile definitions used in other nearby cities.

The commission did not adopt a final ADU code; Noel proposed circulating an Excel worksheet of the policy choices (lot size, setbacks, foundation, utility connections, parking, occupancy and conditional-use criteria) and asked commissioners to prioritize items for the next meeting. Noel emphasized that internal ADUs are already required by state code but that there is no current state mandate for external ADUs. Commissioners asked staff for a prioritized list and suggested additional legal review before formal code language is drafted.

The commission will return to ADU policy in a subsequent meeting after staff compiles suggested edits and the Excel checklist.