Document the condition
Note where the movement or crack shows up, when you first noticed it, whether it tracks with weather, and any earlier repairs at the property. A handful of photos and rough measurements make the first conversation far more useful.
Read the local context
The city's growth from its 1824 plat outward left foundations that fail in distinct ways. The oldest in-town structures rest on stone and unreinforced masonry, where trouble reads as sloping floors and separating walls rather than a single crack. The clapboard housing of the Old West Side and its bungalow and Tudor infill sits on shallow footings on small lots with little room to excavate. The county's postwar subdivisions are conventional block and poured construction. Beneath all three, frost heave and moisture movement in glacial clay produce seasonal rather than steadily progressive movement.
Ask what will be hidden
Cracks and sticking doors are clues, not diagnoses: around Ann Arbor, glacial till clay loam along the Huron River means grading, drainage, framing, and foundation type all need to be weighed together before a repair plan is proposed. Whatever gets covered back up on an Ann Arbor job — drainage tie-ins, prep work, fasteners — belongs in the written scope, described before it disappears.
Compare complete scopes
Line up Ann Arbor proposals side by side on protection, access, materials, permits, testing, cleanup, restoration, exclusions, warranties, and how change orders are handled.
What official local sources add
The overlay's freeboard requirement — lowest floor at least a foot above the mapped 0.2%-annual-chance elevation — tells you how the city thinks about below-grade risk, and on a parcel inside it, extensive structural work can engage those standards. Beneath the regulation sit two physical mechanisms southern guidance does not describe: glacial till and clay that hold water against foundations and swell, and frost heave that lifts seasonally. A diagnosis naming only one of the two is incomplete.
Sources were reviewed 2026-07-19. Check parcel-specific expansive-soil conditions, historic-district status, and current permit rules for the Ann Arbor parcel in question with the relevant authority before authorizing work.