Throwing up a sash is not just some line Clement Moore said in his 'Twas the Night before Christmas', it was actually something people did back in that time and still do today. In fact, every time you open up your sash windows, you are throwing up a sash or the moveable part of the window, but you may call it opening a window.
Archie Campbell
Sash windows have been around for centuries and have remained popular to this day because of their aesthetic appeal. They are made up of two wooden panels containing glass inserts. One or both of the panels or frames is able to move, usually vertically, to open or close the window. The weights for this action are hidden in what is known as a Yorkshire light and the earliest example can be seen in Vermeers painting of The Milk Maid, dated 1658.
Sash Windows Can Beautify Your Stylish Property
Two of the more common ways for homeowners to increase their home's energy efficiency is to install either secondary- or double-glazed windows. Both of these systems work relatively well for cutting heating and cooling costs and for reducing the 'carbon foot print' of the dwelling. They are not, however, equal in efficiency. There is a significant problem, for example, with secondary glazing and condensation build-up.