Historic commission approves mudroom and garage ADU at 808 West Washington; narrowly clears large roof dormer with staff condition

On March 13, 2025, the Ann Arbor Historic District Commission approved a rear mudroom enlargement and a new two‑car garage with a second‑story accessory dwelling unit (ADU) at 808 West Washington Street, a contributing property in the Old West Side Historic District. The commission also approved a 23‑foot‑wide shed dormer on the main roof and removal of a rear chimney after a split vote and a condition that the dormer siding be visually differentiated and reviewed by staff.

The project had two parts on the agenda: (1) rebuild a non‑historic rear mudroom (a roughly 24 square‑foot increase) and construct a 27‑foot‑2‑inch by 27‑foot‑7‑inch garage with an ADU above it; and (2) add a 23‑foot‑wide shed dormer on the south slope of the main house roof and remove a rear chimney. Staff presented the history of the 1900 house and recommended caution on the dormer while expressing no objection to the mudroom or ADU.

The staff report warned that the proposed dormer “does not meet the Secretary of the Interior standards 2 and 9 and the Ann Arbor Historic District design guidelines,” saying its width and height would substantially change the house’s historic roof shape. The staff presentation noted the dormer would be approximately 23 feet wide and roughly 7 feet tall at the eastern face, with the top set 6–8 inches below the ridge, and that the ADU footprint is substantial at about 736 square feet.

Applicant Chuck Boltman and owner Mark Higgins — who joined remotely and said the ADU would house a family member — told commissioners the dormer size is driven by building code egress requirements and the need for usable headroom. Boltman said the dormer framing would improve roof strength and that the dormer is removable in the future, a point he linked to the Secretary of the Interior Standards’ advice that additions be removable without harming the historic fabric.

Commissioners debated the dormer’s impact on the house’s character and on a short row of three highly similar houses. Some members said they were persuaded that a dormer was historically used on similar houses and preferable to a larger backyard addition; others said the dormer’s massing disrupted the house’s steep, vertical roof character. Several commissioners said a visual differentiation between historic fabric and new work would reduce harm.

Commissioner Fortner moved approval of the mudroom and the garage/ADU; the commission approved that motion without recorded opposition. Fortner later moved approval of the dormer and chimney removal; the motion passed 3–1. As part of that approval, the commission required that the siding on the dormer be differentiated from the house (for example, a different reveal or siding exposure) and that the final siding profile be approved by staff before work proceeds.

This split vote reflects the commission balancing the property owner’s desire to create functional modern living space and code‑required egress against the commission’s mandate to preserve the building’s defining historic roof shape. The commission likewise accepted removal of the rear chimney given its limited visibility.

What the approvals mean: the owners may proceed to obtain city permits for the approved work, but the dormer siding detail must be submitted for staff review and approval. The commission’s motions referenced the Secretary of the Interior Standards for Rehabilitation and the Ann Arbor Historic District Design Guidelines as governing standards.

Commission discussion highlights

• Staff concerns: Ms. Thatcher (historic district staff) told the commission the dormer is “nearly the full width of the roof” and “significantly changes the historic roof shape,” citing Standards 2 and 9.

• Applicant justification: contractor Chuck Boltman said the dormer height is driven by the need for an egress window and usable headroom in a habitable attic space and that the dormer could be removed in the future if desired.

• Compromise reached: commissioners asked the applicant to change the dormer siding reveal or material so the dormer reads as new work; the applicant agreed to work with staff and to an administrative review of the siding reveal. The final vote approving the dormer incorporated that staff‑approval condition.

Next steps and limits

The commission recorded approval for the mudroom/garage ADU and approval for the dormer and chimney removal (as amended). The owner must obtain required city permits and submit the dormer siding detail for staff review. The commission’s approvals rely on the work being undertaken as shown to the commission; significant changes will require return to the commission.

Ending note

The commission framed the decision as a careful compromise: commissioners who worried about roof massing were swayed by code and usability arguments and by a material‑differentiation condition intended to preserve the legibility of the house’s historic form.