Windows contain clues to a building's history. Caring for Your Old Windows O riginal and old windows are the most threatened element in preservation today, despite the fact that they are character-defining features of both the exterior and interior of a historic building. The replacement window industry aggressively markets to owners who don't know what to do with their rattling windows. Replacing an old window with a factory-made model destroys the rich variety of window details that makes each old house unique. Fortunately, there exist sensitive, cost-effective solutions for the owner to consider before plunking down hundreds of dollars to buy a modern replacement.
Cold air blows in around the sash because they have to be loose enough to operate.
Over time the surfaces wear, enlarging the space. The solution is to insert weatherstripping between the sash and the frame and where the sash meet. If your window has a pulley at the top of the frame, that is another source of cold air. Cover this with a self-stick pulley cover, available at many home improvement stores. Storm windows .