History of the Sash Window
Sash Window Origins
There has been much speculation about the true origins of the sash window. Many accounts a a claim the design originates in Spain, France or Holland.Thou British historians will argue that it was invented in good old England, and the design of the box sash window was attributed to the English Inventor Robert hook.
In the late seventeenth century, pulleys and weights were first applied to timber sashes and the vertical sliding box sash window was born. The new style of window soon caught on and they were installed throughout Britain in the 1680s and 1690s.
The term sash describes any window where the glazed panels are opening either in a vertical or swinging movement.
By the middle of the century the familiar Georgian window with six or eight panes to each sash had become commonplace.
These very early windows have chunky timber members subdividing sashes into very small panes to suit the limited size of poor quality glass which was available at that time.
As the Georgian era gave way to the Victorian, so sash windows changed as well. Partly based on improved technology (particularly in glass), but mostly on the classic Victorian desire for embellished designs, sash windows grew more ornate.
The simple lines of Georgian windows gave way to ornate architraves, window trims and stone surrounds.From the beginning of the late eighteenth century fewer subdivisions and larger, heavier glass became common.
As large panes became fashionable old sashes with multiple small panes were sometimes altered their glazing bars removed and re-glazed with larger panes of plate glass.
The death of Queen Victoria in 1901 ushered in the new Edwardian era. For sash windows this meant a return to the simple, clean, elegant lines of Georgian windows, but often on a much larger scale.
During Edwardian times sash windows became huge-regularly floor to ceiling heights, and five foot widths.
A trend towards larger paned, smaller paned sash windows with chunky glazing bars became popular.Often windows of this period combined multiple small paned upper sash – very often with horns – with a single or two pane lower sash.
This expanse of glass was much heavier than in the earlier windows and increased stress was put on the joints. The sash horn was developed to overcome this problem. Sash horns also evolved in their design over time. No window had horns prior to 1850.
Upper sashes from this period sometimes incorporate stained glass a feature that was to remain in vogue into the 1930s.
After reigning supreme in all types of buildings from castle to croft for two and a half centuries, the sash window finally fell out of widespread use in the 1950s.
Glass technology has evolved through out the historical period with many distinct types influencing the design and development of the sash window. Crown glass and cylinder glass are two processes which were continually refined. Cylinder glass was made from blown cylinders of lass cut and rolled flat on a sanded surface. After the 1830s the length of glass which could be blown was greatly improved and thickness was reduced.
It’s distinct imperfections which are characteristic of a sanded surface, bubbles and other marks which tend to be linear. Crown glass as made from a large bubble of glass being spun out by a very skilled process to form a disc of glass producing the ripple effect characteristic of the material (though sometimes hard to spot on the finest examples).
Slimlite Double Glazed units can be heat-treated to give a subtle warp to the surface to match the crown glass of yesteryear. Click here to find out more…
These are some basic historical facts we have put together, but if you want to dig a little deeper click here.