Windows in Wisconsin leak heat for as many months as they leak rain. A rail that whistles in November is still whistling in March. North rooms show it first. Fog between panes means the seal is done. Frost on the room side of a single pane is a cold-glass problem, not a mysterious leak. Wood sash that stays wet under a storm panel will rot the sill while you are waiting for spring.
Drafts in this cold are a comfort problem and, on a bad night, a pipe problem if the line shares that wall. Say so if that is your layout. Failed storms rattle, and they also trap moisture against the wood. A unit that misses a thick old wall leaks at the casing in wind-driven snow. Divided lites on a farmhouse facade may be something you mean to keep.
Tell the call how many openings hurt, which floor, and whether the complaint is draft, fog, rot, or a sash painted shut. A bedroom that must open is a different urgency from a fogged stair light. Condensation that feeds the trim all winter is quietly destroying the stool. If you only need cords, locks, or a storm panel, say that. A whole-house speech wastes the first minute.
Ask what happens to interior trim, the stool, and the exterior casing. Village houses with original wood deserve a scope that says what is saved. Newer rural ranches may be a straight unit swap if the flange and the wrap are sound. Either way, the opening has to be square enough to seal, and this climate will find the gap. Hardware and screens can wait; a hole you can feel with your hand cannot.
Lead with the town and the wall that faces the weather. Draft, fog, rot, or a stuck sash is enough. Say if a supply line shares the cold wall. Wisconsin will run that leak all the way through the heating months. Call the number on this page.