Windows in Virginia take humidity from the coast into the foothills, salt near the beaches, and hard drafts in the mountains. Wood sash in older brick towns swells and then gaps. Newer insulated units fog when the seal fails. A rotten sill on the ocean side is not the same repair as a drafty sash on a ridge. Describe the opening and the direction it faces.
Brick openings and old wood frames shed water in their own way. If the stool is soft, the leak is at the joint, not a reason to swap only the glass. Painted-shut sash, failed cords, and locks that miss are separate from a milky pane. Coastal hardware pits. Mountain paint fails at the bottom rail where meltwater sits. Say which of those you see, and say whether original trim should stay.
A bath window that sweats is a moisture problem tied to the room. A stair window in a tall brick house takes more weather than a small bath hopper. Storms on the coast drive rain at the windward wall. Ice inland finds the same joint from the other direction. End walls and weather sides fail first. Interior rooms on a townhouse may have almost no glass, so the openings you do have matter more.
You do not need every unit counted. One room, the weather wall, or the whole house is enough. Mention a bedroom toward the water, a historic front you want kept, or screens that no longer fit if that is the actual issue. Old paint that will be disturbed belongs in the description. A house under heavy shade stays damp at the sill even when the glass looks fine.
Look at the lower rail before you call. Windows in Virginia fail from salt, from humid air, or from mountain cold, depending on where the house stands between the coast and the ridges. Call the number on this page.