Document the condition
Record where dampness appears in the Ann Arbor home, its relationship to rain or snowmelt on the property's slope, and prior repair attempts. A few photos and measurements help frame the first call.
Read the local context
A town platted in 1824 and built out steadily since has below-grade space from every era, and that is the first thing to establish. The nineteenth-century core carries stone and unreinforced masonry that seeps through the wall itself rather than at an identifiable crack. The Old West Side's frame houses sit on shallower footings than later practice allows. The postwar subdivisions across Washtenaw County brought poured and block walls whose exterior drainage varied by builder and year. Under all of them, glacial till and clay hold water against the wall and deep frost opens and closes paths seasonally.
Ask what will be hidden
On Ann Arbor's hilly moraine lots, water can enter from several directions at once — surface runoff, grading that slopes toward the house, hydrostatic pressure from the glacial till below, cracked walls, or failed floor joints — and telling them apart is the first job, not the last. The written scope should explain what Ann Arbor preparation and verification will no longer be visible once the job is complete.
Compare complete scopes
A complete Ann Arbor proposal addresses protection, access, materials, permits, testing, cleanup, restoration, exclusions, warranties, and change-order pricing -- confirm each one is there before comparing totals.
What official local sources add
The 2021 overlay district is the provision that reaches below-grade work most directly. Requiring a lowest floor at least a foot above the mapped 0.2%-annual-chance elevation is a standard above the federal minimum, and it signals how seriously the city treats below-grade space near mapped risk. On a parcel inside that overlay, what a basement may become is a regulated question rather than a design preference. The Community Rating System Class 6 rating matters to you as a flood-insurance premium discount, which is worth knowing if below-grade finishing is part of the plan.
Last checked 2026-07-19. Confirm the Ann Arbor parcel's flood zone, historic-district status, and permit requirements directly with the city before work begins.