Windows in Wilmington live in brick openings on the hills and in the older streets below the fall line. Wood sash, tall and often painted, still faces a lot of those blocks. River humidity swells the wood. A winter on the high ground finds every gap. Fogged newer units in later houses are a different repair from a rotten sill on a mill-era brick wall. Say which one you are looking at.
The brick and the frame meet in a joint that takes water when wind drives rain up the Brandywine valley or across the river flats. If the stool is soft, the glass is not the whole job. Weights and cords fail in the old sash, and a meeting rail that will not lock is a separate complaint from a milky pane. Stone lintels and brick molds are worth describing so the work fits the opening.
Houses on the hills often have more glass on the weather side, with trees that shade one elevation and leave another baking. Houses nearer the Christina may have fewer chances for sun and more lingering damp at the sill. A bath window that sweats onto plaster is a moisture problem tied to the room. Say the floor, the direction, and whether the sash moves or is painted in place.
You do not need every window counted. Say the street facade, the garden side, or the whole house. Mention trim you want kept, a stair window in a tall brick house, or hardware salted by damp rather than by ocean spray. This is a river city on the fall line, not a beach. Old paint that will be disturbed belongs in the description.
Look at the lower rail before you call. Windows in Wilmington fail where brick, wood, and river air meet, with a colder draft on the hills above the Brandywine. Bring the wall and the symptom. Call the number on this page.