The world's oldest stained glass window (which is still standing) is conventionally believed to be in Augsburg Cathedral in the German state of Bavaria. Depicting the prophets David, Jonah, Daniel, Moses and Hosea, it is estimated to be nearly 1,000 years old, having undergone significant bombing during World War II. Long before that, however, mankind had been working with glass, and while today we have thin frames with crystalline sheets and a variety of properties, we had to come a long way to get here. In this article we will tell you a little about the evolution of glass windows and the technologies and possibilities that we have today.
From natural glass to churches
During prehistoric times, naturally produced glass, such as obsidian, was used for tool tips, weapons and even as currency. It is estimated that the first manufactured glass dates back to 3,500 B.C. in the Mesopotamian region, made through a rather slow and complex process. It was then modernized by Syrian craftsmen who introduced the blown glass technique, making it faster, easier and cheaper.
The Roman civilization, learning of this manufacturing technique, perfected these methods and by the 1st century A.D., the quality of glass as a material had improved and was being made at a larger scale. It was at this time that the first glass windows began to appear, allowing some natural light to pass into interiors, and in the 4th century, stained glass windows –composed of several colored vitreous fragments– began to be incorporated into churches, depicting biblical scenes that added a component of beauty to the buildings.
Successive inventions and improvements
An invention that increased the potential for windows was made in 1674, making it possible to manufacture larger panes of glass. It was called Crown Glass, made by blowing out a large glass globe, then cutting and flattening it. The result was still an opaque glass, composed of several circular segments. As early as 1834 the method of making glass by cylinder was developed in Germany. But it was the development of the Float Glass method, which is today's industry standard, that allowed for larger panes.
The Float Glass process involves molten glass poured into a bed of molten metal (usually tin), and then slowly cooled to form a smooth, flat surface on both sides. The glass is then cut to the desired size and shape. One of the main advantages of Float Glass is that it can be produced in large sheets, up to several meters in size, which makes it more efficient to produce and also reduces the need to cut and mill the glass.
The evolution and possibilities of window frames
Along with these advancements, something that eventually became equally as important was the evolution of frames. At first, they were made of small squares of wood or iron, and today the possibilities are infinite, both aesthetically and functionally, adapting to the most demanding needs for energy efficiency and sealing. Made of aluminum, PVC, fiberglass and other modern materials, they allow large and heavy glass panes (often double and triple) to be structured, with drive systems that are highly precise and light to operate. The dimensions of the openings have always depended on the prevailing technology and the budget available. Today, however, floor-to-ceiling and reinforced glass frames have become more affordable, creating greater dialog between the indoors and outdoors.
Western Windows Systems specializes in producing extremely discreet and efficient glass frames that meet the highest standards for builders, architects and customers. For example, to meet technical efficiency standards, products in the company's Performance Line adhere to National Fenestration Ratings Council (NFRC) testing and rating requirements, meaning that solar heat gain coefficients and U-factor values meet the standards for resisting solar radiation and preventing heat from escaping from a room, as well as sealing any gaps that may create airflows. The company also offers solutions to improve acoustic comfort, an important consideration in modern architectural designs thanks to increasing urbanization, worsening noise pollution, and a greater awareness of the connections between noise exposure and various health problems.
The Series 300 Minimalist Multi-Slide Door is another example of the innovation of extremely narrow, hidden locking frames. Allowing a virtually seamless connection between inside and outside, and a wide range of finish options, it gives spaces a minimalist aesthetic while providing security, energy efficiency and opening options. Large panels, slim lines and low-emissivity double glazing offer beautiful ways to minimize the boundaries between indoors and outdoors.
But beyond structuring large glass panes, another technological achievement has been the ability to move them safely and easily. Sliding systems –also called moving glass walls– allow to blur the connection between indoors and outdoors far beyond the purely visual, expanding living spaces and allowing occupants to connect to nature. While most moving glass walls are a maximum of 80 inches high, Western Window Systems' products can be taller and wider, providing more natural light and expanded views. The 7600 Series multi-line door, for example, is available in heights up to 15 feet in most areas. This is done through highly efficient aluminium profiles, which in addition to providing structural rigidity and light handling, are super slim, with safe movements supported by stainless-steel rolling hardware.
The glass industry works around the clock to develop new products and improve the quality of spaces by combining the technologies of glass manufacturing with those of strong, practical frames. As Le Corbusier once said, "The history of architecture is also the history of windows", since they provide our connection to the outside environment while we are safe and sheltered, as well as allowing sunlight and ventilation to enter our indoor spaces.
