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.

After years of controversy, experts now believe they were originally invented in Yorkshire. 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 were a huge improvement over their predecessors, both aesthetically and practically, and were incorporated into older homes as well as being favored for new buildings. The window tax of the 18th and 19th centuries caused many of these fashionable windows to be taken out again, however.During the Georgian era, sash windows became what they are today, with the development of the two moving sashes. 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 are considered characteristic of the Regency style.

The popularity of these windows have remained strong during the Victorian age, but they were ornamented with elaborate decorations. Gradated windows, diminishing in size with the height of the building, and large bay windows are characteristic of this period. Sashes with four panes of glass are another mark of the Victorian window. While the absence of glazing bars was originally a status symbol, many people put in windows that imitated older styles once sheet glass had become cheaper and more commonly used during the late 19th century.

Sash windows have become far less common during the last century, despite being the favorite style at the beginning of the 20th century, due to the increase in cheap, mass-produced styles of window. Recently people have begun to take an interest in the historic character of their homes, resulting in greater demand for traditional style sash windows. Sash windows today use all the latest technology, but retain the elegance and functionality of traditional sashes, and preserve the historic style of the older houses.