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 material, a sash set in a frame in the opening. The sash and frame are also referred to as a window. Many glazed windows may be opened, to allow ventilation, or closed to exclude inclement weather. Windows may have a latch or similar mechanism to lock the window shut or to hold it open by various amounts.
Types include the eyebrow window, fixed windows, hexagonal windows, single-hung, and double-hung sash windows, horizontal sliding sash windows, casement windows, awning windows, hopper windows, tilt, and slide windows, tilt and turn windows, transom windows, sidelight windows, jalousie or louvered windows, clerestory windows, lancet windows, skylights, roof windows, roof lanterns, bay windows, oriel windows, thermal, or Diocletian, windows, picture windows, rose windows, emergency exit windows, stained glass windows, French windows, panel windows, double/triple-paned windows, and witch windows.
Etymology
The English language-word window originates from the Old Norse vindauga, from vindr 'wind' and auga 'eye'. In Norwegian, Nynorsk, and Icelandic, the Old Norse form has survived to this day. In Swedish, the word vindöga remains as a term for a hole through the roof of a hut, and in the Danish language vindue and Norwegian Bokmål vindu, the direct link to eye is lost, just as for window. The Danish word is pronounced fairly similarly to window.Window is first recorded in the early 13th century, and originally referred to an unglazed hole in a roof. Window replaced the Old English eagþyrl, which literally means 'eye-hole', and eagduru 'eye-door'. Many Germanic languages, however, adopted the Latin word fenestra to describe a window with glass, such as standard Swedish fönster, or German Fenster. The use of window in English is probably because of the Scandinavian influence on the English language by means of loanwords during the Viking Age. In English, the word fenester was used as a parallel until the mid-18th century. Fenestration is still used to describe the arrangement of windows within a façade, as well as defenestration, meaning 'to throw out of a window'.
History
The Romans were the first known to use glass for windows, a technology likely first produced in Roman Egypt, in Alexandria AD. Presentations of windows can be seen in ancient Egyptian wall art and sculptures from Assyria. Paper windows were economical and widely used in ancient China, Korea, and Japan. In England, glass became common in the windows of ordinary homes only in the early 17th century whereas windows made up of panes of flattened animal horn were used as early as the 14th century. In the 19th century American west, greased paper windows came to be used by pioneering settlers. Modern-style floor-to-ceiling windows became possible only after the industrial plate glass making processes were fully perfected.Technologies
In the 13th century BC, the earliest windows were unglazed openings in a roof to admit light during the day. Later, windows were covered with animal hide, cloth, or wood. Shutters that could be opened and closed came next. Over time, windows were built that both protected the inhabitants from the elements and transmitted light, using multiple small pieces of translucent material, such as flattened pieces of translucent animal horn, paper sheets, thin slices of marble, or pieces of glass, set in frameworks of wood, iron or lead. In the Far East, paper was used to fill windows.The Romans were the first known users of glass for windows, exploiting a technology likely first developed in Roman Egypt. Specifically, in Alexandria 100 CE, cast-glass windows, albeit with poor optical properties, began to appear, but these were small thick productions, little more than blown-glass jars flattened out into sheets with circular striation patterns throughout. It would be over a millennium before window glass became transparent enough to see through clearly, as we expect now. In 1154, Al-Idrisi described glass windows as a feature of the palace belonging to the king of the Ghana Empire.
Over the centuries techniques were developed to shear through one side of a blown glass cylinder and produce thinner rectangular window panes from the same amount of glass material. This gave rise to tall narrow windows, usually separated by a vertical support called a mullion. Mullioned glass windows were the windows of choice among the European well-to-do, whereas paper windows were economical and widely used in ancient China, Korea, and Japan. In England, glass became common in the windows of ordinary homes only in the early 17th century, whereas windows made up of panes of flattened animal horn were used as early as the 14th century.
Modern-style floor-to-ceiling windows became possible only after the industrial plate glass-making processes were perfected in the late 19th century. Modern windows are usually filled using glass, although transparent plastic is also used.
Fashions and trends
The introduction of lancet windows into Western European church architecture from the 12th century CE built on a tradition of arched windows inserted between columns, and led not only to tracery and elaborate stained-glass windows but also to a long-standing motif of pointed or rounded window-shapes in ecclesiastical buildings, still seen in many churches today.Peter Smith discusses overall trends in early-modern rural Welsh window architecture:
Up to about 1680 windows tended to be horizontal in proportion, a shape suitable for lighting the low-ceilinged rooms that had resulted from the insertion of the upper floor into the hall-house. After that date vertically proportioned windows came into fashion, partly at least as a response to the Renaissance taste for the high ceiling. Since 1914 the wheel has come full circle and a horizontally proportioned window is again favoured.
The spread of plate-glass technology made possible the introduction of picture windows.
Many modern day windows may have a window screen or mesh, often made of aluminum or fibreglass, to keep bugs out when the window is opened. Windows are primarily designed to facilitate a vital connection with the outdoors, offering those within the confines of the building visual access to the everchanging events occurring outside. The provision of this connection serves as an integral safeguard for the health and well-being of those inhabiting buildings, lest they experience the detrimental effects of enclosed buildings devoid of windows. Among the myriad criteria for the design of windows, several pivotal criteria have emerged in daylight standards: location, time, weather, nature, and people. Of these criteria, windows that are designed to provide views of nature are considered to be the most important by people.
Types
Cross
A cross-window is a rectangular window usually divided into four lights by a mullion and transom that form a Latin cross.Eyebrow
The term eyebrow window is used in two ways: a curved top window in a wall or an eyebrow dormer; and a row of small windows usually under the front eaves such as the James-Lorah House in Pennsylvania.Fixed
A fixed window is a window that cannot be opened, whose function is limited to allowing light to enter. Clerestory windows in church architecture are often fixed. Transom windows may be fixed or operable. This type of window is used in situations where light or vision alone is needed as no ventilation is possible in such windows without the use of trickle vents or overglass vents.Single-hung sash
A single-hung sash window is a window that has one sash that is movable and the other fixed. This is the earlier form of sliding sash window and is also cheaper.Double-hung sash
A sash window is the traditional style of window in the United Kingdom, and many other places that were formerly colonized by the UK, with two parts that overlap slightly and slide up and down inside the frame. The two parts are not necessarily the same size; where the upper sash is smaller it is termed a cottage window. Currently, most new double-hung sash windows use spring balances to support the sashes, but traditionally, counterweights held in boxes on either side of the window were used. These were and are attached to the sashes using pulleys of either braided cord or, later, purpose-made chain. Three types of spring balances are called a tape or clock spring balance; channel or block-and-tackle balance, and a spiral or tube balance.Double-hung sash windows were traditionally often fitted with shutters. Sash windows can be fitted with simplex hinges that let the window be locked into hinges on one side, while the rope on the other side is detached—so the window can be opened for fire escape or cleaning.