Window in the context of Beam (optics)

A building or edifice is an enclosed structure with a roof, walls and often windows, usually standing permanently in one place, such as a house or factory. Buildings come in a variety of sizes, shapes, and functions, and have been adapted throughout history for numerous factors, from building materials available, to weather conditions, land prices, ground conditions, specific uses, prestige, and aesthetic reasons. To better understand the concept, see Nonbuilding structure for contrast.

Buildings serve several societal needs – occupancy, primarily as shelter from weather, security, living space, privacy, to store belongings, and to comfortably live and work. A building as a shelter represents a physical separation of the human habitat (a place of comfort and safety) from the outside (a place that may be harsh and harmful at times).

Stained glass refers to coloured glass as a material or art and architectural works created from it. Although it is traditionally made in flat panels and used as windows, the creations of modern stained glass artists also include three-dimensional structures and sculpture. Modern vernacular usage has often extended the term "stained glass" to include domestic lead light and objets d'art created from glasswork, for example in the famous lamps of Louis Comfort Tiffany.

As a material stained glass is glass that has been coloured by adding metallic salts during its manufacture. It may then be further decorated in various ways. The coloured glass may be crafted into a stained-glass window, say, in which small pieces of glass are arranged to form patterns or pictures, held together (traditionally) by strips of lead, called cames or calms, and supported by a rigid frame. Painted details and yellow-coloured silver stain are often used to enhance the design. The term stained glass is also applied to enamelled glass in which the colors have been painted onto the glass and then fused to the glass in a kiln.

Glass is an amorphous (non-crystalline) solid. Because it is often transparent and chemically inert, glass has found widespread practical, technological, and decorative use in window panes, tableware, and optics. Some common objects made of glass are named after the material, e.g., a "glass" for drinking, "glasses" for vision correction, and a "magnifying glass".

Glass is most often formed by rapid cooling (quenching) of the molten form. Some glasses such as volcanic glass are naturally occurring, and obsidian has been used to make arrowheads and knives since the Stone Age. Archaeological evidence suggests glassmaking dates back to at least 3600 BC in Mesopotamia, Egypt, or Syria. The earliest known glass objects were beads, perhaps created accidentally during metalworking or the production of faience, which is a form of pottery using lead glazes.

A light beam or beam of light is a directional projection of light energy radiating from a light source. Sunlight forms a light beam (a sunbeam) when filtered through media such as clouds, foliage, or windows. To artificially produce a light beam, a lamp and a parabolic reflector is used in many lighting devices such as spotlights, car headlights, PAR Cans, and LED housings. Light from certain types of laser has the smallest possible beam divergence.

Daylighting is the practice of placing windows, skylights, other openings, and reflective surfaces so that direct or indirect sunlight can provide effective internal lighting. Particular attention is given to daylighting while designing a building when the aim is to maximize visual comfort or to reduce energy use. Energy savings can be achieved from the reduced use of artificial (electric) lighting or from passive solar heating. Artificial lighting energy use can be reduced by simply installing fewer electric lights where daylight is present or by automatically dimming or switching off electric lights in response to the presence of daylight – a process known as daylight harvesting.

The amount of daylight received in an internal space can be analyzed by measuring illuminance on a grid or undertaking a daylight factor calculation. Computer programs such as Radiance allow an architect or engineer to quickly calculate benefits of a particular design. The human eye's response to light is non-linear, so a more even distribution of the same amount of light makes a room appear brighter.

Rose window is often used as a generic term applied to a circular window, but is especially used for those found in Gothic cathedrals and churches. The windows are divided into segments by stone mullions and tracery. The term rose window was not used before the 17th century and comes from the English flower name rose.

The name "wheel window" is often applied to a window divided by simple spokes radiating from a central boss or opening, while the term "rose window" is reserved for those windows, sometimes of a highly complex design, which can be seen to bear similarity to a multi-petalled rose. Rose windows are also called "Catherine windows" after Saint Catherine of Alexandria, who was sentenced to be executed on a spiked breaking wheel. A circular window without tracery such as are found in many Italian churches, is referred to as an ocular window or oculus.

A lintel or lintol is a type of beam (a horizontal structural element) that spans openings such as portals, doors, windows and fireplaces. It can be a decorative architectural element, or a combined ornamented/structural item. In the case of windows, the bottom span is referred to as a sill, but, unlike a lintel, does not serve to bear a load to ensure the integrity of the wall.Modern-day lintels may be made using prestressed concrete and are also referred to as beams in beam-and-block slabs or as ribs in rib-and-block slabs. These prestressed concrete lintels and blocks can serve as components that are packed together and propped to form a suspended-floor concrete slab.

An arch functions as a curved lintel.

Sapphire is a precious gemstone, a variety of the mineral corundum, consisting of aluminium oxide (α-Al₂O₃) with trace amounts of elements such as iron, titanium, cobalt, lead, chromium, vanadium, magnesium, boron, and silicon. The name sapphire is derived from the Latin word sapphirus, itself from the Greek word sappheiros (σάπφειρος), which referred to lapis lazuli. It is typically blue, but natural "fancy" sapphires also occur in yellow, purple, orange, and green colors; "parti sapphires" show two or more colors. Red corundum stones also occur, but are called rubies rather than sapphires. Pink-colored corundum may be classified either as ruby or sapphire depending on the locale. Commonly, natural sapphires are cut and polished into gemstones and worn in jewelry. They also may be created synthetically in laboratories for industrial or decorative purposes in large crystal boules. Because of the remarkable hardness of sapphires – 9 on the Mohs scale (the third-hardest mineral, after diamond at 10 and moissanite at 9.5) – sapphires are also used in some non-ornamental applications, such as infrared optical components, high-durability windows, wristwatch crystals and movement bearings, and very thin electronic wafers, which are used as the insulating substrates of special-purpose solid-state electronics such as integrated circuits and GaN-based blue LEDs. It occurs in association with ruby, zircon, biotite, muscovite, calcite, dravite and quartz.

A lancet window is a tall, narrow window with a sharp pointed arch at its top. This arch may or may not be a steep lancet arch (in which the compass centres for drawing the arch fall outside the opening). It acquired the "lancet" name from its resemblance to a lance. Instances of this architectural element are typical of Gothic church edifices of the earliest period. Lancet windows may occur singly, or paired under a single moulding, or grouped in an odd number with the tallest window at the centre.

The lancet window first appeared in the early French Gothic period (c. 1140–1200), and later in the Early English period of Gothic architecture (1200–1275). So common was the lancet window feature that this era is sometimes known as the "Lancet Period".

Stained glass refers to coloured glass as a material or art and architectural works created from it. Although it is traditionally made in flat panels and used as windows, the creations of modern stained glass artists also include three-dimensional structures and sculpture. Modern vernacular usage has often extended the term "stained glass" to include domestic lead light and objets d'art created from glasswork, for example in the famous lamps of Louis Comfort Tiffany.

As a material stained glass is glass that has been coloured by adding metallic salts during its manufacture. It may then be further decorated in various ways. The coloured glass may be crafted into a stained-glass window, in which small pieces of glass are arranged to form patterns or pictures, held together (traditionally) by strips of lead, called cames or calms, and supported by a rigid frame. Painted details and yellow-coloured silver stain are often used to enhance the design. The term stained glass is also applied to enamelled glass in which the colors have been painted onto the glass and then fused to the glass in a kiln.

In architecture, an atrium (pl.: atria or atriums) is a large open-air or skylight-covered space surrounded by a building.Atria were a common feature in Ancient Roman dwellings, providing light and ventilation to the interior. Modern atria, as developed in the late 19th and 20th centuries, are often several stories high, with a glazed roof or large windows, and often located immediately beyond a building's main entrance doors (in the lobby).

Atria are a popular design feature because they give their buildings a "feeling of space and light." The atrium has become a key feature of many buildings in recent years. Atria are popular with building users, building designers and building developers. Users like atria because they create a dynamic and stimulating interior that provides shelter from the external environment while maintaining a visual link with that environment. Designers enjoy the opportunity to create new types of spaces in buildings, and developers see atria as prestigious amenities that can increase commercial value and appeal.

A clerestory (/ˈklɪərstɔːri/ KLEER-stor-ee; lit. 'clear storey', also clearstory, clearstorey, or overstorey; from Old French: cler estor) is a high section of wall that contains windows above eye-level. Its purpose is to admit light, fresh air, or both.

Historically, a clerestory formed an upper level of a Roman basilica or of the nave of a Romanesque or Gothic church, the walls of which rise above the rooflines of the lower aisles and which are pierced with windows.

Glazing, which derives from the Middle English for 'glass', is a part of a wall or window, made of glass. Glazing also describes the work done by a professional "glazier". Glazing is also less commonly used to describe the insertion of ophthalmic lenses into an eyeglass frame.

Common types of glazing that are used in architectural applications include clear and tinted float glass, tempered glass, and laminated glass as well as a variety of coated glasses, all of which can be glazed singly or as double, or even triple, glazing units. Ordinary clear glass has a slight green tinge, but special colorless glasses are offered by several manufacturers.

A hexagonal window (also Melnikov's or honeycomb window) is a hexagon-shaped window, resembling a bee cell or crystal lattice of graphite. The window can be vertically or horizontally oriented, openable or fixed. It can also be regular or elongately-shaped and can have a separator (mullion).

Typically, the cellular window is used for an attic or as a decorative feature, but it can also be a major architectural element to provide the natural lighting inside buildings. The hexagonal window is relatively rare and associated with such architectural styles as constructivism, functionalism and, occasionally, cubism.

A casement window is a window that is attached to its frame by one or more hinges at the side. They are used singly or in pairs within a common frame, in which case they are hinged on the outside. Casement windows are often held open using a casement stay. Windows hinged at the top are referred to as awning windows, and ones hinged at the bottom are called hoppers.

A roof window or garret 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 light and fresh air into the space.

A roof window is different from a tubular skylight in that the light is not directed through any type of channel or tube in order to provide lighting for the interior of a building. This type of light tube design is often employed with buildings where the installation of a skylight or roof window is not practical.

A bay window is a window space projecting outward from the main walls of a building and forming a bay in a room. A bow window is a form of bay with a curve rather than angular facets; an oriel window is a bay window that does not touch the ground.

A window may be all three: projecting outward from the main fascia of a wall, curved in shape, and not reaching the ground. A bay window may be supported from the ground by a foundation, or in space by corbels, brackets, or cantilever.

A display window, also a shop window (British English) or store window (American English), is a window in a shop displaying items for sale or otherwise designed to attract customers to the store. Usually, the term refers to larger windows in the front façade of the shop.