Window replacement costs in Ann Arbor

Ann Arbor's Historic District Commission starts from repair. Its window guidelines say the commission generally requires repair and maintenance of windows in historic buildings. Only windows and parts deteriorated beyond repair, such as deep rot, missing pieces or big gaps around the frame, will be considered for replacement.

Repair can go a long way first. The guidelines list sash cord replacement, re-caulking and new paint as normal upkeep, and new wood or epoxy in sills, jambs or sash for windows in somewhat good shape. A sash too far gone to repair can be replaced on its own with one of like material and identical layout, and insulated glass is allowed in it.

When a window does qualify, staff can approve it without a full commission hearing, as long as the new one matches the old in size, type, location, material and muntin pattern. Bare metal finishes are out, and so is low-E glass that's reflective or tinted, unless it matches what's there. Swapping a window that wasn't original is also on the staff list. Each window slated for replacement needs its own specifications form, and the commission keeps a list of local firms and people who know old windows.

Most of the city's housing is from before 1980, about six in ten homes, the Census Bureau estimates.