Windows in Illinois take prairie wind and then humid air. A meeting rail that whistles in January is a heat leak all heating season. A sash that swells in a southern July may stick shut until fall. Hail can spider a pane without touching the roof next to it. Old wood units and newer insulated glass fail in different ways, and the call should say which you have.
Fog between panes means the seal failed and the glass is done as insulation, even if it still stops rain. A rotten sill is not the same complaint as a fogged unit. Wind-driven rain at a brick opening often enters beside the window, not through the glass. Look for stained plaster at the corners before you blame the sash. Loose storm windows rattle all winter and trap moisture on the wood.
Say which floor, which wall, and whether the problem is draft, water, fog, or a pane you cannot see through. North walls in older towns show the draft first. West walls take the storms. A bedroom window that sweats all winter may be feeding the paint and the trim around it. If a child sleeps in that room, say so, because a stuck sash is more than an annoyance.
Replacement is not the only sentence. A cord, a lock, a storm panel, or a reglaze can be the whole job if the frame and sill are solid. Ask what stays and what goes. Paint, interior trim, and the exterior wrap all change how the opening looks when the work is finished. On brick, the joint at the brickmold has to be part of the plan.
Tell the town and how many openings are actually failing, without turning it into a whole-house speech. Draft, leak, fog, or broken glass is enough to start. Name the wall that faces the weather. Bring a note about storms that rattle only on the west side. Illinois wind will find the one you skip. Call the number on this page.