Window

A window is an opening in an otherwise solid and opaque surface that allows the passage of light and air. Windows are usually glazed or covered in some other transparent or translucent material.

Etymology

The word Window originates from the Old Norse vindauga, from vindr "wind" and auga "eye." "Vindauga" is still used in Icelandic, as well as some Norwegian dialects to mean exactly the same thing: window. It is first recorded in the early 13th century, and originally referred to an unglazed hole in a roof. Window replaced the Old English eagÐ"Ñ*yrl, which literally means "eye-hole," and eagduru, "eye-door". Most Germanic languages however adopted the Latin word fenestra to describe a window with glass, such as Swedish fÐ"¶nster, or German Fenster. Notable exceptions to this, apart from English, are Danish and Norwegian, with the English word window closely resembling the words vindue and vindu respectively. This is probably due to 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-1700s and fenestration is still used to describe the arrangement of windows within a facade.

Definition and types of windows

A window is an opening in a wall that lets light and possibly air into the room and allows occupants to see out. Primitive windows were just holes. Later, they 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: mullioned glass windows, which joined multiple small pieces of glass with leading, paper windows, flattened pieces of translucent animal horn, and plates of thinly sliced marble. Mullioned glass windows were the windows of choice among European well-to-do, whereas paper windows were economical and widely used in ancient China 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[citation needed] were used as early as the 14th century in Northern Britain. Modern-style floor-to-ceiling windows became possible only after the industrial glass making process was perfected. Evidence of glass window panes in Italy dates back nearly 3000 years.

Modern windows are customarily large rectangles or squares with glass surfaces. Churches traditionally have stained glass windows.

Today a window can be made in practically any square and Window style 10cm squared

Modern domestic windows come in many styles. The choice of design varies throughout the world, and is largely dictated by the prevailing weather conditions. Coastal climates tend to have smaller outward-opening windows due to the stronger winds experienced - e.g. England. Continental climates tend to have larger windows, many of which open inwards - e.g. France and Germany. Styles available include:

Double-hung sash window

The traditional style of window in the USA, and many other places that were formerly colonized by the UK, with two parts (sashes) that overlap slightly and slide up and down inside the frame. The two parts are not necessarily the same size. Nowadays, most new double-hung sash windows use spring balances to support the sashes, but traditionally, counterweights held in boxes 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. Double-hung sash windows were traditionally often fitted with shutters. Sash windows may be fitted with simplex hinges which allow the window to be locked into hinges on one side, while the rope on the other site is detached, allowing the window to be opened for escape or cleaning.

Single-hung sash window

One sash is movable (usually the bottom one) and the other fixed. This is the earlier form of sliding sash window, and is obviously also cheaper.

Horizontal sliding sash window

Has two or more sashes that overlap slightly but slide horizontally within the frame. In the UK, these are sometimes called Yorkshire sash windows, presumably because of their traditional use in that county.

Casement window

A window with a hinged sash that swings in or out like a door comprising either a side-hung, top-hung, or occasionally bottom-hung sash or a combination of these types, sometimes with fixed panels on one or more sides of the sash. In the USA these are usually opened using a crank, but in Europe they tend to use projection friction stays and espagnolette locking. Formerly, plain hinges were used with a casement stay. Handing applies to casement windows to determine direction of swing.

Tilt and slide

A window (more usually a door-sized window) where the sash tilts inwards at the top and then slides horizontally behind the fixed pane.

Tilt and turn

A window which can either tilt inwards at the top, or can open inwards hinged at the side.

Transom window

A window above a door; if an exterior door the transom window is often fixed, if an interior door it can often open either by hinges at top or bottom, or can rotate about hinges at the middle of its sides. It provided ventilation before forced air heating and cooling.

Jalousie window

A window comprised of many slats of glass that open and close like a Venetian blind, usually using a crank. The hinges may be at the top or middle of each of the slats of glass. A Jalousie door is a door with a Jalousie window.

Clerestory window

A vertical window set in a roof structure or high in a wall, used for daylighting.

Skylight

A flat or sloped window built into a roof structure for daylighting

Roof Lantern

A roof lantern is a multi-paned glass structure, resembling a small building, built on a roof for day or moon light. Sometimes includes an additional Clerestory.