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.

Despite much debate, the sash window is now thought to have originated in Yorkshire, England. Sash windows were designed to allow a small gap for ventilation without letting in the rain, and were also less prone to rotting and distortion due to their enclosure within 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. Many were later removed, however in order to avoid paying the window tax of the late 18th/early 19th centuries. The Georgian sash window took on the modern double sash form. Glass was still expensive and marked with central bull’s eyes by the manufacture process. Once larger panels became available the classic six-paned Georgian windows appeared. 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. 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. 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. Demand has recently grown again due to increased awareness of architectural history. Modern versions of the sash window preserve the traditional character of older properties, while combining all the latest developments in manufacturing processes with the grace and practicality that this style epitomizes.