![Stralsund, st Nikolai (2007-01-24) d](https://upload.wikimedia.org/wikipedia/commons/c/c5/Stralsund%2C_st_Nikolai_%282007-01-24%29_d.JPG)
In
architecture
Architecture is the art and technique of designing and building, as distinguished from the skills associated with construction. It is both the process and the product of sketching, conceiving, planning, designing, and constructing building ...
, a clerestory ( ; , also clearstory, clearstorey, or overstorey) is a high section of wall that contains
window
A window is an opening in a wall, door, roof, or vehicle that allows the exchange of light and may also allow the passage of sound and sometimes air. Modern windows are usually glazed or covered in some other transparent or translucent materia ...
s above eye level. Its purpose is to admit light, fresh air, or both.
Historically, ''clerestory'' denoted an upper level of a Roman
basilica
In Ancient Roman architecture, a basilica is a large public building with multiple functions, typically built alongside the town's forum. The basilica was in the Latin West equivalent to a stoa in the Greek East. The building gave its name ...
or of the
nave
The nave () is the central part of a church, stretching from the (normally western) main entrance or rear wall, to the transepts, or in a church without transepts, to the chancel. When a church contains side aisles, as in a basilica-type ...
of a
Romanesque or
Gothic
Gothic or Gothics may refer to:
People and languages
*Goths or Gothic people, the ethnonym of a group of East Germanic tribes
**Gothic language, an extinct East Germanic language spoken by the Goths
**Crimean Gothic, the Gothic language spoken b ...
church
Church may refer to:
Religion
* Church (building), a building for Christian religious activities
* Church (congregation), a local congregation of a Christian denomination
* Church service, a formalized period of Christian communal worship
* C ...
, the walls of which rise above the rooflines of the lower
aisle
An aisle is, in general, a space for walking with rows of non-walking spaces on both sides. Aisles with seating on both sides can be seen in airplanes, certain types of buildings, such as churches, cathedrals, synagogues, meeting halls, parl ...
s and are pierced with windows.
Similar structures have been used in transportation vehicles to provide additional lighting, ventilation, or headroom.
History
Ancient world
The technology of the clerestory appears to originate in the
temples
A temple (from the Latin ) is a building reserved for spiritual rituals and activities such as prayer and sacrifice. Religions which erect temples include Christianity (whose temples are typically called churches), Hinduism (whose temples ...
of
ancient Egypt. The term "clerestory" is applicable to Egyptian temples, 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. Clerestory appeared in Egypt at least as early as the
Amarna period.
In the
Minoan
The Minoan civilization was a Bronze Age Aegean civilization on the island of Crete and other Aegean Islands, whose earliest beginnings were from 3500BC, with the complex urban civilization beginning around 2000BC, and then declining from 1450B ...
palaces of
Crete
Crete ( el, Κρήτη, translit=, Modern: , Ancient: ) is the largest and most populous of the Greek islands, the 88th largest island in the world and the fifth largest island in the Mediterranean Sea, after Sicily, Sardinia, Cyprus, and ...
such as
Knossos
Knossos (also Cnossos, both pronounced ; grc, Κνωσός, Knōsós, ; Linear B: ''Ko-no-so'') is the largest Bronze Age archaeological site on Crete and has been called Europe's oldest city.
Settled as early as the Neolithic period, the na ...
, by contrast,
lightwell
In architecture, a lightwell,light well, light-well sky-well,skywell, sky well or air shaft is an unroofed or roofed external space provided within the volume of a large building to allow light and air to reach what would otherwise be a dark or ...
s were employed in addition to clerestories.
According to Biblical accounts, the Hebrew
temple
A temple (from the Latin ) is a building reserved for spiritual rituals and activities such as prayer and sacrifice. Religions which erect temples include Christianity (whose temples are typically called churches), Hinduism (whose temples ...
built by
King Solomon featured clerestory windows made possible by the use of a tall, angled roof and a central .
The clerestory was used in the
Hellenistic architecture
Hellenistic art is the art of the Hellenistic period generally taken to begin with the death of Alexander the Great in 323 BC and end with the conquest of the Greek world by the Romans, a process well underway by 146 BCE, when the Greek mainlan ...
of the later periods of
ancient Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
civilization. The Romans applied clerestories to
basilica
In Ancient Roman architecture, a basilica is a large public building with multiple functions, typically built alongside the town's forum. The basilica was in the Latin West equivalent to a stoa in the Greek East. The building gave its name ...
s of justice and to the basilica-like bath-houses and palaces.
Early Christian and Byzantine basilicas
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
The nave () is the central part of a church, stretching from the (normally western) main entrance or rear wall, to the transepts, or in a church without transepts, to the chancel. When a church contains side aisles, as in a basilica-type ...
flanked by lower aisles on each side. The nave and aisles are separated by columns or piers, above which rises a wall pierced by clerestory windows.
Romanesque period
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
A barrel vault, also known as a tunnel vault, wagon vault or wagonhead vault, is an architectural element formed by the extrusion of a single curve (or pair of curves, in the case of a pointed barrel vault) along a given distance. The curves are ...
ceilings with no clerestory. The development of the
groin vault
A groin vault or groined vault (also sometimes known as a double barrel vault or cross vault) is produced by the intersection at right angles of two barrel vaults. Honour, H. and J. Fleming, (2009) ''A World History of Art''. 7th edn. London: Lau ...
and
ribbed vault
A rib vault or ribbed vault is an architectural feature for covering a wide space, such as a church nave, composed of a framework of crossed or diagonal arched ribs. Variations were used in Roman architecture, Byzantine architecture, Islamic a ...
made possible the insertion of clerestory windows.
Initially the nave of a large aisled and clerestoried church was of two levels:
arcade
Arcade most often refers to:
* Arcade game, a coin-operated game machine
** Arcade cabinet, housing which holds an arcade game's hardware
** Arcade system board, a standardized printed circuit board
* Amusement arcade, a place with arcade games
* ...
and clerestory. During the Romanesque period, a third level was inserted between them, a gallery called the "
triforium
A triforium is an interior gallery, opening onto the tall central space of a building at an upper level. In a church, it opens onto the nave from above the side aisles; it may occur at the level of the clerestory windows, or it may be locat ...
". 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. This feature is found in some late Romanesque and early Gothic buildings in France.
The oldest glass clerestory windows still in place are from the late eleventh century, found in
Augsburg Cathedral in
Bavaria
Bavaria ( ; ), officially the Free State of Bavaria (german: Freistaat Bayern, link=no ), is a state in the south-east of Germany. With an area of , Bavaria is the largest German state by land area, comprising roughly a fifth of the total lan ...
, Germany.
Gothic period
![Cathedrale d'Amiens - Grandes verrieres et voutes de la nef](https://upload.wikimedia.org/wikipedia/commons/0/0c/Cathedrale_d%27Amiens_-_Grandes_verrieres_et_voutes_de_la_nef.jpg)
In smaller churches, clerestory windows may be
trefoil
A trefoil () is a graphic form composed of the outline of three overlapping rings, used in architecture and Christian symbolism, among other areas. The term is also applied to other symbols with a threefold shape. A similar shape with four ring ...
s or
quatrefoil
A quatrefoil (anciently caterfoil) is a decorative element consisting of a symmetrical shape which forms the overall outline of four partially overlapping circles of the same diameter. It is found in art, architecture, heraldry and traditional ...
s. In some Italian churches they are
ocular
Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and con ...
. In most large churches, they are an important feature, both for beauty and for utility. The
ribbed vault
A rib vault or ribbed vault is an architectural feature for covering a wide space, such as a church nave, composed of a framework of crossed or diagonal arched ribs. Variations were used in Roman architecture, Byzantine architecture, Islamic a ...
ing and
flying buttress
The flying buttress (''arc-boutant'', arch buttress) is a specific form of buttress composed of an arch that extends from the upper portion of a wall to a pier of great mass, in order to convey lateral forces to the ground that are necessary to pu ...
es of Gothic architecture concentrated the weight and thrust of the roof, freeing wall-space for larger clerestory
fenestration
Fenestration may refer to:
* Fenestration (architecture), the design, construction, or presence of openings in a building
* Used in relation to fenestra in anatomy, medicine and biology
* Fenestration, holes in the rudder
A rudder is a primar ...
. Generally, in Gothic masterpieces, the clerestory is divided into
bays by the vaulting shafts that continue the same tall columns that form the arcade separating the aisles from the nave.
The tendency from the early Romanesque period to the late Gothic period was for the clerestory level to become progressively taller and the size of the windows to get proportionally larger in relation to wall surface, emerging in works such as the Gothic architecture of
Amiens Cathedral
, image = 0 Amiens - Cathédrale Notre-Dame (1).JPG
, imagesize = 200px
, img capt = Amiens Cathedral
, pushpin map = France
, pushpin label position = below
, coordinates =
, country ...
or
Westminster Abbey
Westminster Abbey, formally titled the Collegiate Church of Saint Peter at Westminster, is an historic, mainly Gothic church in the City of Westminster, London, England, just to the west of the Palace of Westminster. It is one of the United ...
, where their clerestories account for nearly a third of the height of the interior.
Modern clerestory windows for energy-efficient buildings
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. Factory buildings often are built with clerestory windows; modern housing designs sometimes include them as well.
Modern clerestory windows may have another especially important role, besides
daylighting
Daylighting is the practice of placing windows, skylights, other openings, and Reflective surfaces (climate engineering), reflective surfaces so that sunlight (direct or indirect) can provide effective internal lighting. Particular attention is ...
and
ventilation
Ventilation may refer to:
* Ventilation (physiology), the movement of air between the environment and the lungs via inhalation and exhalation
** Mechanical ventilation, in medicine, using artificial methods to assist breathing
*** Ventilator, a m ...
: they can be part of
passive solar
In passive solar building design, windows, walls, and floors are made to collect, store, reflect, and distribute solar energy, in the form of heat in the winter and reject solar heat in the summer. This is called passive solar design because, unli ...
strategies, in very energy-efficient buildings (
passive house
"Passive house" (german: Passivhaus) is a voluntary standard for energy efficiency in a building, which reduces the building's ecological footprint. It results in ultra-low energy buildings that require little energy for space heating or coo ...
s and
zero-energy building
A Zero Energy Building (ZEB), also known as a Net Zero Energy (NZE) building, is a building with net zero energy consumption, meaning the total amount of energy used by the building on an annual basis is equal to the amount of renewable energy ...
s).
To that end, clerestories are used in conjunction with stone, brick, concrete, and other high-mass walls and floors, properly positioned to store
solar heat gain
Solar gain (also known as solar heat gain or passive solar gain) is the increase in thermal energy of a space, object or structure as it absorbs incident solar radiation. The amount of solar gain a space experiences is a function of the total in ...
s during the hotter parts of the day – allowing the walls and the floor to act as a heat bank during the cooler parts of the day.
Clerestories – in passive solar strategies – should be properly located (typically in the sunny side of the building) and protected from the summer's sun by rooflines,
overhangs, recessed thick walls, or other architectural elements, in order to prevent overheating during the cooling season.
Transportation
Clerestory roofs were used on
railway carriages (known as "clerestory carriages") from the mid-nineteenth century to the 1930s.
The first
Pullman coaches in England had clerestory roofs, and were imported and assembled at Derby, where Pullman set up an assembly plant in conjunction with the
Midland Railway
The Midland Railway (MR) was a railway company in the United Kingdom from 1844. The Midland was one of the largest railway companies in Britain in the early 20th century, and the largest employer in Derby, where it had its headquarters. It am ...
, a predecessor of the
London Midland and Scottish Railway
The London, Midland and Scottish Railway (LMSIt has been argued that the initials LMSR should be used to be consistent with LNER, GWR and SR. The London, Midland and Scottish Railway's corporate image used LMS, and this is what is generally ...
(LMS). The first coach, a sleeping car named "Midland", was assembled and ready for trial-running in January 1874.
The last clerestory-roofed trains on the
London Underground
The London Underground (also known simply as the Underground or by its nickname the Tube) is a rapid transit system serving Greater London and some parts of the adjacent ceremonial counties of England, counties of Buckinghamshire, Essex and He ...
were the
'Q' stock, which were withdrawn from operation in 1971.
Clerestories were also used in early
double-decker bus
A double-decker bus or double-deck bus is a bus that has two storeys or decks. They are used for mass transport in the United Kingdom, the United States, New Zealand, Europe, Asia and also in cities such as Sydney; the best-known example is the ...
es, giving better
ventilation
Ventilation may refer to:
* Ventilation (physiology), the movement of air between the environment and the lungs via inhalation and exhalation
** Mechanical ventilation, in medicine, using artificial methods to assist breathing
*** Ventilator, a m ...
and headroom in the centre corridor, as well as better
illumination.
The
Volkswagen Type 2
The Volkswagen Type 2, known officially (depending on body type) as the Transporter, Kombi or Microbus, or, informally, as the Bus (US), Camper (UK) or Bulli (Germany), is a forward control light commercial vehicle introduced in 1950 by the Ge ...
Kombi, or Transport, commonly called the Microbus, came in a deluxe version with clerestory windows. VW made the Samba from 1961 to 1967 in several versions, which had as many as 23 windows, and it is highly prized by collectors.
The clerestory is known as "mollycroft roof", as well, especially in
Romany and other caravans, eg,
vardos.
See also
*
Säteritak, a Swedish roof style with a strip of clerestory-type of windows halfway up a hip roof
*
Architecture of cathedrals and great churches
The architecture of cathedrals and great churches is characterised by the buildings' large scale and follows one of several branching traditions of form, function and style that derive ultimately from the Early Christian architectural traditi ...
*
Gothic architecture
Gothic architecture (or pointed architecture) is an architectural style that was prevalent in Europe from the late 12th to the 16th century, during the High and Late Middle Ages, surviving into the 17th and 18th centuries in some areas. It e ...
*
Passive daylighting
Passive may refer to:
* Passive voice, a grammatical voice common in many languages, see also Pseudopassive
* Passive language, a language from which an interpreter works
* Passivity (behavior), the condition of submitting to the influence of o ...
*
Romanesque architecture
Romanesque architecture is an architectural style of medieval Europe characterized by semi-circular arches. There is no consensus for the beginning date of the Romanesque style, with proposals ranging from the 6th to the 11th century, this lat ...
*
Roof window
A roof window is an outward opening window that is incorporated as part of the design of a roof. Often confused with a skylight, a roof window differs in a few basic ways. A roof window is often a good option when there is a desire to allow both ...
References
External links
Clerestory coach (railway) images- nineteenth-century examples from more than 20 countries
{{Use dmy dates, date=March 2017
Church architecture
Windows
Architectural elements
Energy-saving lighting
Sustainable building