Sash windows are a key feature for many traditional period buildings. Sash windows were traditionally built using timber, which is fairly high maintenance and has a tendency toward rotting and warping. Over time, these windows can become draughty and insecure. uPVC sash windows are a great way to experience the benefits of modern double glazing, without sacrificing the aesthetic of your home. uPVC sash windows will not rot or warp and require little maintenance. They are also thermally efficient, which means that your home will not require as much heating.