Oak Grove board directs staff to allow attached ADUs with conditions after lengthy debate

The Oak Grove Board of Alderwomen on June 23 directed staff to amend a proposed accessory dwelling unit (ADU) ordinance to allow attached ADUs under specified conditions, after weeks of Planning and Zoning review and significant discussion at the meeting.

Matt Randall, city staff, told the board the Planning and Zoning Commission originally recommended ADUs be detached and suggested a size approach tying ADU livable area to the principal residence: the maximum livable square footage would be whichever is greater of 400 square feet or 40% of the primary home's finished area, but in no case exceeding 900 square feet. Randall said ADUs must meet building code, obtain a building permit, and that prohibited ADU building types include mobile homes, shipping containers and temporary structures.

Randall offered the board three actions: approve the ordinance as proposed, deny it or direct staff to return with revisions. Board members raised concerns about neighborhood character, emergency access and the practical needs of families or caretakers. Scott (staff member) described conversations with nurses who preferred detached ADUs because they can access a patient directly: “they disliked the attached because they can't often find how to get into the facility to the person to treat,” he said.

After discussion, a board member made a motion to amend the proposed ADU ordinance to allow attached ADUs, with a 10-foot setback for attached units (5 feet for detached), direction for staff to review utilities and related code impacts, and a condition that an attached ADU not have a front-facing door. The motion was seconded and passed by voice vote; the board did not adopt the ordinance at the meeting and instead directed staff to return a revised ordinance reflecting the changes.

Key elements of the proposed ADU rules that the board discussed include: one ADU per principal structure/lot; ADUs must be on the same lot as the principal residence and the primary structure must have a current certificate of occupancy; ADUs must meet the most recent International Residential Code; side and rear setbacks were recommended at 10 feet (greater than typical 8-foot accessory-structure setbacks because ADUs are inhabited); ADUs cannot be located in required front setbacks and must be at least 5 feet behind the principal façade; ADUs are required to provide one additional off-street parking space beyond the primary structure’s requirement; ADUs may share utilities or have separate utilities but must have external emergency disconnects for specified services.

On use and occupancy, the Planning and Zoning recommendation — reflected in the draft — stated the ADU or primary structure may be rented only if the property owner resides in either the ADU or the primary structure, and any rental period must be for at least 30 days.

Randall emphasized the intent of the ADU language: “An accessory dwelling unit is a secondary or subordinate residential dwelling unit located on the same lot as the primary residence. It provides a self-contained housekeeping unit with its own kitchen, bathroom, and sleeping area,” language he presented while explaining the draft.

Next steps: staff will return a revised ordinance that allows attached ADUs with the directed conditions and will provide recommended language on setbacks, utilities and door placement for board consideration and potential final adoption.