The Evolution of The Window


I wake up in the morning, all groggy eyed and messy hair. I am not ready for the bouncing upbeat energy my kids have to offer me in these early hours, so I walk as silently as I can to the kitchen. I avoid all the familiar squeaky spots in the old wooden floor. I enter the kitchen and am immediately hit with a blast of thick, hot air. We do not have a portable air conditioner in the kitchen like we do in the other rooms of our apartment. I decide to start a cup of coffee and open the old wood windows in the kitchen. Letting in the fresh, cool morning air is the perfect medication for this situation. I honestly do not give it a second thought.

There are many inventions in our modern lives that we take for granted. One such invention is that of the modern window. Where did windows come from?

The very first window was an opening cut into or built into a roof. These openings did not have any glass. They did not have any sort of protective covering at all. They were designed in the 13th century B.C. to let outside light into a home during the day. These original windows had their benefits but there were also some major and obvious drawbacks. Any type of weather would be an issue, the more obvious weather issues are rain and snow. However, sun damage would have been an issue as well especially during the summer months. Dirt from wind blowing as well as pests such as rodents, flies, and other bugs would have been able to get into the home easily. While these windows served their purpose, they were not very practical. Could you imagine intentionally living with a large hole in your roof?

Around the 14th century B.C. people began to use materials such as stretched animal hide, cloth, or wood to cover these openings and get a small amount of protection from the elements.

Windows that completely protected people from weather and debris that also allowed natural light to enter the living space slowly evolved. People began using thin pieces of marble, flattened animal horns, and eventually glass. The first people to use glass in windows were the Romans, in the year 100 AD. The glass they created was a relatively small cube of glass that was super thick. This glass allowed a certain amount of light to enter a building, but visibility was exceptionally low.  (It would still be another millennium before more modern see-through glass was made.)

In 17th century England, people figured out how to use the square pieces of Roman glass to make larger, thinner, rectangular pieces of glass. They would roll out the thick cubes and cut them into thin rectangular shapes. The rectangles were thinner, but they were not smooth, and visibility was still low. Using two pieces of the painstakingly crafted rectangular glass mulled together people created a mullioned window. Mullioned windows became extremely popular among the wealthiest inhabitants of Europe and East Asia. The less fortunate in Europe still commonly used animal hide or flattened pieces of animal horn. Whereas a greased paper window was popular in ancient China, Korea, and Japan.

It was not until the year 1952 that the modern smooth dual paned insulated glass window unit was born. The insulated glass or IG unit was 18 years old before it became popular and widespread.

Most IG units today are made with glass. Some however are made with a plastic material. Modern windows have a lot of options. Including triple paned IG units which help lessen condensation and reduce cold drafts from winter air. They also help keep the heat out during the summer. Contrary to popular belief they do not help much with noise reduction. 

Laminated IG units on the other hand were created specifically to help with noise reduction. In this case the glass is coated in a plastic or resin type of material.

Then there is Low-E or low emissivity glass. In this case there is a microscopically thin coating on the glass that is transparent and reflects heat. One of the major benefits to having Low-E glass is that you get an energy savings. It should more then pay for itself after you start saving on your energy bills. Low-E glass comes in different levels each level having their own Low-E rating. Including solar control Low-E glass; A type of Low-E glass designed to help keep building cooler in the summer and warmer in the winter.

Windows today are designed to illuminate our lives. They allow the comfort of fresh air to enter our living space and provide much needed ventilation while also offering us protection from the elements. The evolution of the window was painstaking and slow. Next time you open your window, maybe you will take a moment to appreciate its process. I know I will.