History of the Box Sash Window
Early Developments
Early in the 18th Century, what is thought of as the classic glazing pattern of the Georgian window developed. This design, six panes over six panes, remained in use even after the advent of larger panes in the 19th Century, particularly in cheaper properties.
At this point it is worth mentioning something about the construction of the window. In buildings such as Hampton Court Palace, sash windows frame were constructed in a similar way to today, built out of sections. However a method that was widely used well into the 1720's, and probably later, was to make sash windows frame out of solid sections pegged together in the same way as casement windows were, with the style hollowed out to allow enough room for one sash weight on each side. Usually only the lower sash was made to operate on these
early windows.
Another interesting mechanism, which can often be used as a useful dating guide, is the sash pulley itself, i.e. the wheel which the cord passes over, and which is attached to the sash weight. In early sash windows, this wheel was of brass where funds permitted, or boxwood or oak. The wheel was set either with a pin directly into the frame, or into a separate wooden block, to facilitate removal and repair. The construction of the pulley case varied considerably and these early sash windows were often quite simple, compared with the exquisite
joinery of the later Georgian period.