Clerestory windows are often used in spaces that are much farther away from external walls. Because of this, there is no natural lighting coming to these areas. Hence, the need for clerestory windows in otherwise, windowless spaces became a necessity. These windows are placed higher than the surrounding roofs to light interior spaces.
Ancient Egyptians were among the first civilizations that used this technology to light up dark spaces. The windows were present in the hall of columns in the form of slits made in vertical slabs of stone. This technology appeared in Egypt during the Amarna period.
Ancient World
Clerestory windows were introduced in the ancient Egyptian civilization. The technology was used to bring light into interior spaces. The initial clerestory windows were seen in railway carriages before they were seen in Egyptian temples with columns. In the Minoan palaces of Crete, light wells were added along with clerestories.
Clerestories were then used in Hellenistic architecture (Greek civilization). The Romans applied clerestories to basilicas of justice and the basilica-like-bath-houses and palaces. Clerestory roofs were used on railway carriages (known as “clerestory carriages”) from the mid-nineteenth century to the 1930s.
If you look into the history of clerestory windows, the concept is simple. For very tall walls in an enclosed space, to get easy access to light and ventilation, we can create some openings on the top so that light can seep into the otherwise dark room. This way, there is even a play of light and shadows in the room which can be interesting for the users. The light and shadow even create different patterns based on the time of the day and position of openings.
Efforts to place slits can be seen in the Temple of Karnak in ancient Egypt. The Chartres cathedral (1194), for example, has pairs of lancet clerestory windows that are almost as wide as the aisle windows.
During the Roman Empire, the design had involved the construction of arched openings on public buildings. Some of the examples of architecture include the Baths of Diocletian (3rd century AD) and the Basilica of Constantine (AD 310–320), both in Rome.
In Byzantine and Early Christian architecture, clerestory windows can be seen under the side arches of Hagia Sophia in Constantinople (532–563).
Clerestories In The Modern World
They say that windows are the eyes of the building, and eyes are the windows to the soul.
It is, therefore, very important to have the right kind of windows in any building. The true clerestory window as we see today appeared in the medieval era.
The Gothic period architects created large spaces with open and airy spaces. They introduced flying buttresses to build large structures. This reduced internal supports to a great extent and the buttresses were strong enough to allow numerous openings.
From this came a tradition of filling the upper level of the cathedral with a row of large glass windows. This tradition has continued to the present day. In other words, a ‘clear story’ of glass was added to the structure, and the name originated from this.
Modern clerestories are placed in factory buildings and modern housing designs. They are located on high walls, extending up from the roofline. They are sometimes referred to as vertical windows. Its main purpose is to provide light and breeze into a place with very access to them both.
Clerestory windows are an option for ventilation and lighting that doesn’t compromise privacy. Another, very useful purpose of these windows is that they can be part of passive solar strategies. This ensures that the buildings which have them are more energy-efficient than those which don’t have clerestory windows.
Natural lighting in buildings is very important to its users to provide a visual connection between the interior and exterior spaces. Clerestory, in architecture, is any windowed wall of a room that is carried higher than the surrounding roof, to light the interior space.
Nowadays, the ribbon windows of glass are replaced with individual windows and are commonly seen in traditional houses. Clerestory windows set directly under the eaves of a roof can also make the roof seem to float and hover above the house walls. This visual effect is the reason that clerestories are seen in religious buildings. However, it took longer to be included in smaller-scale domestic architecture.
One of the most important designers was American architect Frank Lloyd Wright who introduced them into modern homes. Examples of designs by Frank Lloyd Wright which have clerestories in them are the Zimmerman House and the Toufic Kalil Home. One of the most recent examples is the Grand Central Terminal in New York City, where the clerestory windows supplemented the gas and electric lighting.
