A History of Glass Windows

July 31, 2024

A Life Without Glass

The earliest windows were, unsurprisingly, made without glass. What may astonish you, however, is the materials used to construct windows back then. Initially, windows were simply openings in the wall to allow natural light to enter. Later, thin animal hides were stretched over these openings to offer some elemental protection while still permitting soft light to filter through. Shutters could be closed in bad weather to protect those inside.

Early Glass

During the Roman era, glassmaking was quite advanced. Panes of glassy pebbles were set in wooden frames that allowed some light through, though they were not transparent. The introduction of clear glass panes occurred in the late 3rd century, when blown glass cylinders were created and then thinly sliced to produce curvy pieces of transparent glass.

Back to Basics

Unfortunately, when the Roman Empire collapsed and history entered the Dark Ages, this technology was lost. Cathedrals continued to create stained glass windows using small pieces of glass, but for the general populace, this was no longer available. The return of wooden shutters and thin animal hides ensued. Windows had to remain small, and insulating the animal hide-covered openings was nearly impossible. People turned to the use of thinly sliced pieces of horn fastened together to provide better insulation, but these windows were costly to produce and saw little use among common homes.

Windows Make A Comeback

In the Middle Ages, glassmakers began to redevelop the glass window. The French developed crown glass – a hollow bubble spun into flattened discs and laced together in lead panes (the image above is a great example of crown glass). Other glassmakers also “rediscovered” the cylinder glass technique used by the Romans over a millennium earlier. This time, however, the technology was here to stay – and glass entered the homes of the wealthy – although it was still incredibly expensive. Nobles would often routinely take their glass panes down and store them carefully when they weren’t in their homes to ensure they were not broken.

Versailles – A Legacy in the Window Industry

In the late 17th century, the French continued improving glass technology, and the clear glass window pane was cast. The Palace of Versailles – built in the 1680s – used this new and expensive technology to create the long-latticed windows that French Doors and Windows are still known for today. Yet again, glass remained quite a luxury. Apart from the wealthy, the common person of this period could only dream of having a clear glass covering for their windows.

Glass for the Masses

Glass continued to be a luxury for many years, despite improved methods for its creation. England eventually repealed duties on windows, reducing its price by about 50% in the early 19th century. People had never seen so many glass windows and could finally afford them!

Later, the use of steel as load-bearing columns in architecture allowed for the installation of “curtain walls.” Large floor-to-ceiling windows could now be used in designs, as the wall no longer needed to support the weight of the structure. This led to the modern skyscraper look of the early 20th century.

The evolution of the glass window is surprisingly recent for an item we routinely take for granted. Many are aware of how much the automotive industry or the internet have revolutionised the lives of ordinary people, but the introduction of glass windows not only changed the designs possible for people – it completely transformed our indoor environment. Insulated windows make temperature control feasible, and large clear windows are shown to increase happiness and productivity! Imagine your office life with the wind, rain, smells, and noises of the outside world constantly pouring in through a hole in the wall, and take a moment to thank your glass windows for all that they contribute to our modern lifestyles.