Sash Windows

Sash windows (also known as sliding sash windows) came to the fore in the late 18th century in England, replacing casement (hinged) windows. A sash window usually comprises two frames one or both of which slide to open the window (usually vertically). The window relies on pullies and weights to keep the window in the open position. Early sash windows had several panes of glass and glazing bars. As designs improved and the price of glass became cheaper, sash windows comprised fewer, larger panes of glass. From the 1850's this was often just one piece at the top and one at the bottom. Such windows often have "horns" at the bottom of the top sash to increase the strength.


Where possible sash windows should be retained rather than replaced with upvc double glazing. Sash windows can often be repaired for less than the cost of replacement pvc windows. it is also possible to get draught proofing kits. It is not normally possible to insert double glazing units into existing sash windows due to the thickness of the units and the weight which is too great for the pulley and weight system.

If the existing window is completely beyond repair, it is possible to have new wooden sash windows made to include double glazed units. These will often utilise a spring balance system in place of the traditional weigjht and pulley to deal with the heavy glass unit.

There are manufacturers of upvc double glazed sliding sash window. These will retain something of the look of the original windows, but without the authentic quality of real wood.