Committee member urges Mount Clemens to recommend accessory dwelling units to planning commission

A committee member identified in the meeting as Eric asked the Mount Clemens commission to recommend allowing accessory dwelling units, or ADUs, in single-family R-1A and R-1B zones and to send a local draft ordinance to the planning commission for consideration. "I ultimately I believe we should recommend to our planning commission to adopt ADUs," he said, urging the commission to use Dexter’s model ordinance as a starting point.

The recommendation came after Eric described two competing bills pending in Lansing — one that would allow ADUs by right in single-family areas and another that would list ADUs among optional measures municipalities could adopt to unlock housing investment. He said SEMCOG and a meeting with a state senator emphasized the local benefit of small-scale units that he described as "little residential things on the same plot of land as a primary residence." He cited Dexter’s experience, saying that after adopting its ordinance the small city of roughly 1.9 square miles and about 5,000 residents saw six ADUs built and at least one additional permit requested.

Why it matters: Commissioners said ADUs could add smaller, more affordable housing options for elderly residents, young adults and smaller households without dramatically changing neighborhood character. Eric and others stressed owner-occupancy requirements and explicit prohibitions on short-term rentals as safeguards. "They also specifically say that ADUs shall not be used as short term rentals," Eric said.

Commissioners asked technical questions about dimensional limits, reassessment and inspections. Eric explained that Dexter’s ordinance sets a 5,000-square-foot minimum lot area for an ADU, noted some numeric thresholds that can require a larger lot (he cited an example in which an 800-square-foot ADU would require a 12,000-square-foot lot in certain cases), and said Dexter caps ADU height at 20 feet. He also described provisions for converting existing sheds or garages into ADUs subject to structural, fire and engineering review, and a neighbor-notification requirement.

The chair and other commissioners raised fiscal and administrative consequences, asking whether building an ADU would trigger reassessment and how the city’s current rental-inspection workload would be affected. A staff member said building-permit activity typically prompts an assessment review, and that rental revenue can factor into reassessments when a unit becomes a rental. The chair noted the city currently has one rental inspector and that a surge in ADU permits could increase inspection caseloads.

Next steps: The commission directed staff to prepare a draft based on the model presented and to coordinate with the planning commission; Eric volunteered to have the draft presented to planning staff. No formal vote was taken during the work session.

Ending: The commission concluded discussion after confirming the planning commission would need to pass any ordinance before it returned to the city commission for final action.