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Window

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A window is an opening built into a wall, door, roof, or vehicle.

Gordijnen aan venster
Gordijnen aan venster

These openings facilitate the exchange of light, sound, and sometimes air. Most modern windows are glazed, meaning they are covered with a transparent or translucent material. This material is held by a sash, which is set into a frame. Together, the sash and the frame are often referred to as the window itself.

New-windows-installed
New-windows-installed

Windows are vital for human well-being because they provide visual access to the outdoors. This connection to nature is considered one of the most important design criteria for people living in buildings.

Windows function by managing the relationship between the interior and the exterior environment.

Passivhaus Fenster Beispiele (blank)
Passivhaus Fenster Beispiele (blank)

Many windows are operable, meaning they can be opened for ventilation or closed to exclude inclement weather. Mechanisms like latches can lock a window shut or hold it open at specific intervals. Some windows also include a mesh screen, made of aluminum or fiberglass, to keep insects out while allowing air to pass. Through various designs, windows allow solar heat to enter a building while preventing warm air from escaping. This process is an important advancement in heating technology.

There are many distinct types of windows defined by how they move and their shapes.

EdenProjectRoof
EdenProjectRoof

Casement windows use a hinged sash that swings inward or outward like a door.

Gordijnen aan venster
Gordijnen aan venster

Sash windows, common in the United Kingdom, feature two parts that slide up and down within a frame. A single-hung sash window has only one movable part, while a double-hung sash window has two. There are also horizontal sliding sash windows, where the sashes move sideways. Other specialized types include awning windows, which are top-hung, and hopper windows.

Foldup window
Foldup window

You might also see a foldup window, which has two equal sashes that fold upward to allow air through the full frame.

Window technology has evolved through many different materials over thousands of years.

Nasir-al molk -1
Nasir-al molk -1

In the 13th century BC, the earliest windows were simply unglazed openings in a roof. Later, people used animal hide, cloth, or wood to cover these openings. To improve light transmission, they used translucent materials like animal horn, paper, or thin slices of marble. In ancient China, Korea, and Japan, paper windows were a very economical choice. In the 19th-century American West, pioneering settlers often used windows made of greased paper.

WaterMill Window LymeRegis
WaterMill Window LymeRegis

It was not until the late 19th century that industrial plate glass-making processes were perfected, allowing for modern floor-to-ceiling windows.

The history of glass windows began with the Romans.

ValenciaCathedral2
ValenciaCathedral2

They were the first known people to use glass for windows, likely using technology from Roman Egypt. Around 100 CE, cast-glass windows appeared in Alexandria. These were made by taking blown-glass cylinders and flattening them into sheets. Because these early sheets had circular striation patterns, they had poor optical properties. It took over a millennium for window glass to become as clear as we expect today. In England, glass only became common in ordinary homes during the early 17th century.

Architectural trends have also changed how windows look over time.

Paris 12-22 (16249805806)
Paris 12-22 (16249805806)

In 12th-century Western Europe, the introduction of lancet windows led to pointed or rounded shapes in churches. In rural Wales, windows were horizontal until about 1680, when they became vertically proportioned to match the high ceilings of the Renaissance. In the 17th century, timber frames and sash windows became popular in Europe. By the 19th century, glazing bars often took on Gothic designs. In the mid-20th century, the spread of plate-glass technology allowed for the rise of the picture window.

The word "window" has a fascinating etymological history.

MorellaSantaMariaWindow
MorellaSantaMariaWindow

It originates from the Old Norse words for "wind" and "eye." In modern Icelandic, a similar form exists as a word for a small open window. In Swedish, the term still refers to a hole through the roof of a hut. The English word was first recorded in the early 13th century. Before this, the English used terms like "eye-hole" or "eye-door." While the word "window" became standard, the term "fenester" was used in English until the mid-18th century. Today, we still use the related term "fenestration" to describe the arrangement of windows on a building's façade.

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🖼️ Images & Media (18)
File:MorellaSantaMariaWindow.jpg
MorellaSantaMariaWindow.jpg
File:ValenciaCathedral2.JPG
ValenciaCathedral2.JPG
File:Foldup window.gif
Foldup window.gif
File:Gordijnen aan venster.JPG
Gordijnen aan venster.JPG
File:Fenêtre à l'australienne - Awning window - (AWS Magnum 616) Light.jpg
Fenêtre à l'australienne - Awning window...
File:Jalousie2.jpg
Jalousie2.jpg
File:Paris 12-22 (16249805806).jpg
Paris 12-22 (16249805806).jpg
File:BurlingtonHousePavementWindow.jpg
BurlingtonHousePavementWindow.jpg
File:EdenProjectRoof.jpg
EdenProjectRoof.jpg
File:2014 Kłodzko, pl. Chrobrego 13 03.JPG
2014 Kłodzko, pl. Chrobrego 13 03.JPG
File:Nasir-al molk -1.jpg
Nasir-al molk -1.jpg
File:New-windows-installed.jpg
New-windows-installed.jpg

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