A clerestory (also clearstory, clearstorey, or overstorey) is a high section of wall that contains windows above eye-level. The term originates from the Old French "cler estor," meaning 'clear storey'.
Clerestory windows date all the way back to ancient Egypt. The use of clerestories-a row of windows well above eye level-stretches all the way back to temples in ancient Egypt. Ancient Egyptians made use of clerestory windows by cutting slits into giant slabs of stone in order to illuminate halls and temples.
Hypostyle Hall at Karnak
Clerestories in Ancient Egyptian Temples
Clerestories appear to originate in Egyptian temples, such as the Great Hypostyle Hall, where the lighting of the hall of columns was obtained over the stone roofs of the adjoining aisles, through gaps left in the vertical slabs of stone.
One of the earliest uses of the clerestory was in the huge hypostyle hall of King Seti I and Ramses II at the Temple of Amon (1349-1197 BC, Karnak, Egypt), in which the central range of columns, higher than those on either side, permitted clerestories to be built of pierced stone slabs.
Read also: The Language of the Pharaohs
The central axis leaves an open space for these windows. The frames holding these window grilles in place were fully inscribed. Piers have scenes of the king face to face with the gods. One of the great window grilles from the Hall. The rhetoric of these architrave texts is quite grandiose and bombastic. The king is described as a god among the gods and as a superhuman warrior, claiming the columns are coated with electrum.
The architraves are interesting in two respects. The light of the Resurrected Christ now shines on the congregation from the Southern window and from the Northern window, the message of St. Gabriel reminds us that the Word became flesh. Gazing upward to the lofty ceilings of the church, the clerestory windows now look especially dark. These are the windows situated toward the bottom edge of the vaulted ceiling.
Below is a reconstruction of the roof and clerestory of the Hypostyle Hall:
Reconstruction of the roof and clerestory of the Hypostyle Hall
The roofing slabs have collapsed. The Hall was somewhat gloomy. These beams are called architraves and many of them still survive.
Read also: Pharaohs: A detailed look
Evolution Through Romanesque and Gothic Architecture
Centuries later, these windows became a standard architectural feature of the upper levels of both Romanesque and Gothic churches, letting in natural light. The clerestory was used in the Hellenistic architecture of classical antiquity.
Early Christian churches and some Byzantine churches, particularly in Italy, are based closely on the Roman basilica, and maintained the form of a central nave flanked by lower aisles on each side. During the Romanesque period, many churches of the basilica form were constructed all over Europe.
Many of these churches have wooden roofs with clerestories below them. Some Romanesque churches have barrel-vaulted ceilings with no clerestory. Initially the nave of a large aisled and clerestoried church was of two levels: arcade and clerestory. During the Romanesque period, a third level was inserted between them, a gallery called the "triforium". The triforium generally opens into space beneath the sloping roof of the aisle. This became a standard feature of later Romanesque and Gothic large abbey and cathedral churches.
Sometimes another gallery set into the wall space above the triforium and below the clerestory. In smaller churches, clerestory windows may be trefoils or quatrefoils. In some Italian churches they are ocular. In most large churches, they are an important feature, both for beauty and for utility.
In Roman architecture many great halls were lighted with clerestories. Usually, groined vaults over the central hall allowed large semicircular windows to be built above the side roofs, as in the tepidarium of the Baths of Diocletian (3rd century AD) and the Basilica of Constantine (AD 310-320), both in Rome. This device was used in Byzantine and Early Christian architecture, as exemplified by the clerestory walls under the side arches of Hagia Sophia in Constantinople (532-563).
Read also: The Art of Ancient Egypt
The clerestory became most highly developed and widely used in the Romanesque and Gothic periods. The ribbed vaulting and flying buttresses of Gothic architecture concentrated the weight and thrust of the roof, freeing wall-space for larger clerestory fenestration.
Clerestory in Amiens Cathedral
Here's a comparison of features in Romanesque and Gothic architecture:
| Feature | Romanesque | Gothic |
|---|---|---|
| Vaulting | Barrel-vaulted ceilings | Ribbed vaulting |
| Buttresses | Simple buttresses | Flying buttresses |
| Clerestory Fenestration | Smaller windows | Larger windows |
Modern Applications
Modern clerestories often are defined as vertical windows, located on high walls, extending up from the roofline, designed to allow light and breezes into a space, without compromising privacy. Today, the architectural feature is employed in modern homes for exactly the same reason, although extra sunlight isn’t the only benefit.
Whereas lower windows can let in sun in a direct and sometimes harsh way, a row of windows up high lets in a more ambient light. Even better if the clerestory windows open, as this allows for air to flow and circulate. As for aesthetics, placing windows higher affords more open wall space at eye level for displaying books, curios, or a gallery-style arrangement of artwork. And when paired with their other lofty cousin, the skylight, clerestories can ensure that a room never feels claustrophobic.
Clerestory, in architecture, any fenestrated (windowed) wall of a room that is carried higher than the surrounding roofs to light the interior space. In a large building, where interior walls are far from the structure’s exterior walls, this method of lighting otherwise enclosed, windowless spaces became a necessity.
While our clerestory windows will be lit artificially, having some light shine through them will give the illusion of greater height to our church and allow our hearts, minds and souls to soar upward towards heaven. We are still short of the necessary funds to light these windows.
Clerestory Windows - 3 Minute Architecture
Popular articles:
tags: #Egypt
