Sash windows are an integral component of 18th and 19th century style. They make practical and aesthetically pleasing alternatives to casements, with their large glass panels and graceful proportions.

Their origin has almost certainly been traced back to Yorkshire in England. They were developed there to keep out wet weather while permitting air to circulate by leaving a narrow opening, and were also protected from rot and distortion by being closed in a box.

Sash windows offered both practical advantages and a more pleasing style than older window designs, and they were popular in both new buildings and as stylish replacements in existing homes. During the mid 18th century the introduction of the window tax caused many windows to be removed. The window with two movable sashes was developed during the Georgian era. Glass was still expensive and marked with central bull’s eyes by the manufacture process. As better methods of making large panes were found, windows with six panels in each sash appeared, becoming characteristic of the Georgian sash window. They became a key part of Regency architecture.

The popularity of these windows have remained strong during the Victorian age, but they were ornamented with elaborate decorations. Sash windows that are gradated in size, becoming smaller at the top of the building are indicative of the style of this time, as are large bay windows. Four paned sashes are more common in houses built at this time. The wealthy often chose to have older styles of window added to their property to distinguish themselves from the increasingly common use of plate glass sash windows with the slimmer glazing bars that were once prized.

During the 20th century, sash windows have tended to disappear from our streets, being replaced by cheaper, mass-produced windows. An interest in conserving historical styles of architecture has recently revived the demand for sash windows, however. These modern versions are produced with all the latest advances in technology, but retain the traditional style and elegance of older sashes, along with their functional design.