Since people have been building houses, there have been openings in these houses. Throughout the centuries, the history of the window has been determined by functional requirements, technical innovations and last but not least, cultural and therefore associated design developments.
While the Egyptians were familiar with translucent panes of alabaster, Mycenaean palaces had no windows and light came into rooms from above. In Roman homes light also initially came into the house via unglazed openings — the atrium illuminated and ventilated the surrounding rooms. However, some public buildings were already equipped with glazed windows: The urban thermal baths of ancient Herculaneum already featured glazed box-type windows that represented a sophisticated technical construction solution for the rooms with different temperatures.
An eye for the wind
In the Germanic-Nordic region, different views prevailed. The closed wall offered protection against the elements — anything that came in from the outside was an enemy. However, the houses did need some way for smoke to escape. This was via an opening in the wall that was referred to as a "wind eye" (from Old Norse, "vindauga" — vind = wind, auga = eye). Openings designed to allow light in had not yet been invented. The weak glow from the fire was the only source of light for the inhabitants of these houses.
In ancient times and the early Middle Ages, people began to close openings in the wall with oiled animal hides, linen cloths or parchment paper to light the interior. These materials were stretched over wooden frames and jammed into the window opening. An alternative was translucent stones such as ground alabaster, marble or agate slabs, which were used in religious buildings.
15 cm maximum
At our latitudes, glazed windows were barely used in the simple houses of farmers, artisans and citizens until the end of the Middle Ages, or were an expensive luxury. If they were used at all, small panes were inserted, as manual manufacture by glass makers, including subsequent shaping, did not allow for large sizes.
The twelfth century saw the arrival of the bull's-eye pane. This was manufactured by blowing a ball that was opened at the bottom and then slung. A round pane approximately 15 cm in diameter was created, with a navel in the centre. The panes were then connected to one another via lead bars. The oldest buildings with glass windows in Germany include the convent at Tegernsee and Augsburg Cathedral, with its prophet windows. Around 1300, glass windows began to be used by the wealthy sections of society in Europe.
As it was still not possible technically to create large panes of glass, for hundreds of years large windows were made up of small pieces of glass. This was how certain structural typologies such as the latticed window came into being. However, the glass was never completely even and was streaked in places as it continued to be difficult to manufacture plate glass.
In 1851, Paxton's Crystal Palace in England set new standards for the manufacture of glass and for architectural design with glass: At 24,7 x 122 cm, the largest panes made from unmounted glass to date were used. It was not until around 1960 that the industrial float method revolutionised the manufacture of plate glass: In a steel basin, the glass melt swims on liquid tin. As glass is lighter, it remains at the top without bonding to the metal. This is the common production method still used today.
Traditional window forms were replaced at the end of the 19th century with the advanced technical developments in steel, glass and reinforced concrete construction. With skeleton construction the façade was finally detached from the construction.
Today, the window is a high-tech product. In addition to design requirements, in particular structural tasks such as heat and sound protection have to be resolved. With the latest technical developments, Internorm is always in step with the times and with a wide range of products, offers solutions for every requirement.