Door
Encyclopedia
A door is a movable structure used to open and close off an entrance, typically consisting of a panel that swings on hinges or that slides or rotates inside of a space.

When open, they admit ventilation
Ventilation (architecture)
Ventilating is the process of "changing" or replacing air in any space to provide high indoor air quality...

 and light
Light
Light or visible light is electromagnetic radiation that is visible to the human eye, and is responsible for the sense of sight. Visible light has wavelength in a range from about 380 nanometres to about 740 nm, with a frequency range of about 405 THz to 790 THz...

. The door is used to control the physical atmosphere
Atmosphere
An atmosphere is a layer of gases that may surround a material body of sufficient mass, and that is held in place by the gravity of the body. An atmosphere may be retained for a longer duration, if the gravity is high and the atmosphere's temperature is low...

 within a space by enclosing the air draft
Air draft
Air draft is the distance from the surface of the water to the highest point on a vessel, similar to the "deep draft" of a vessel which is measured from the surface of the water to the deepest part of the hull below the surface, but "air draft" is expressed as a height, not a depth.The vessel's...

s, so that interiors may be more effectively heated or cooled. Doors are significant in preventing the spread of fire
Fire
Fire is the rapid oxidation of a material in the chemical process of combustion, releasing heat, light, and various reaction products. Slower oxidative processes like rusting or digestion are not included by this definition....

. They also act as a barrier to noise
Noise
In common use, the word noise means any unwanted sound. In both analog and digital electronics, noise is random unwanted perturbation to a wanted signal; it is called noise as a generalisation of the acoustic noise heard when listening to a weak radio transmission with significant electrical noise...

.

They are also used to screen areas of a building for aesthetics, keeping formal and utility areas separate. Doors also have an aesthetic
Aesthetics
Aesthetics is a branch of philosophy dealing with the nature of beauty, art, and taste, and with the creation and appreciation of beauty. It is more scientifically defined as the study of sensory or sensori-emotional values, sometimes called judgments of sentiment and taste...

 role in creating an impression of what lies beyond. Doors are often symbol
Symbol
A symbol is something which represents an idea, a physical entity or a process but is distinct from it. The purpose of a symbol is to communicate meaning. For example, a red octagon may be a symbol for "STOP". On a map, a picture of a tent might represent a campsite. Numerals are symbols for...

ically endowed with ritual
Ritual
A ritual is a set of actions, performed mainly for their symbolic value. It may be prescribed by a religion or by the traditions of a community. The term usually excludes actions which are arbitrarily chosen by the performers....

 purposes, and the guarding or receiving of the key
Key (lock)
A key is an instrument that is used to operate a lock. A typical key consists of two parts: the blade, which slides into the keyway of the lock and distinguishes between different keys, and the bow, which is left protruding so that torque can be applied by the user. The blade is usually intended to...

s to a door, or being granted access to a door can have special significance. Similarly, doors and doorways frequently appear in metaphor
Metaphor
A metaphor is a literary figure of speech that uses an image, story or tangible thing to represent a less tangible thing or some intangible quality or idea; e.g., "Her eyes were glistening jewels." Metaphor may also be used for any rhetorical figures of speech that achieve their effects via...

ical or allegorical
Allegory
Allegory is a demonstrative form of representation explaining meaning other than the words that are spoken. Allegory communicates its message by means of symbolic figures, actions or symbolic representation...

 situations, literature
Literature
Literature is the art of written works, and is not bound to published sources...

 and the arts
The arts
The arts are a vast subdivision of culture, composed of many creative endeavors and disciplines. It is a broader term than "art", which as a description of a field usually means only the visual arts. The arts encompass visual arts, literary arts and the performing arts – music, theatre, dance and...

, often as a portent of change.

Applications

Architectural doors have numerous general and specialized uses. Doors are generally used to separate interior spaces (rooms, closets, etc.) for privacy
Privacy
Privacy is the ability of an individual or group to seclude themselves or information about themselves and thereby reveal themselves selectively...

, convenience
Convenience
Convenience is anything that is intended to save resources or frustration. A convenience store at a petrol station, for example, sells items that have nothing to do with gasoline/petrol, but it saves the consumer from having to go to a grocery store."Convenience" is a very relative term and its...

, security
Security
Security is the degree of protection against danger, damage, loss, and crime. Security as a form of protection are structures and processes that provide or improve security as a condition. The Institute for Security and Open Methodologies in the OSSTMM 3 defines security as "a form of protection...

, and safety
Safety
Safety is the state of being "safe" , the condition of being protected against physical, social, spiritual, financial, political, emotional, occupational, psychological, educational or other types or consequences of failure, damage, error, accidents, harm or any other event which could be...

 reasons. Doors are also used to secure passages into a building from the exterior for reasons of safety and climate
Climate
Climate encompasses the statistics of temperature, humidity, atmospheric pressure, wind, rainfall, atmospheric particle count and other meteorological elemental measurements in a given region over long periods...

 control.

Doors also are applied in more specialized cases:
  • A trapdoor
    Trapdoor
    A trapdoor is a door set into a floor or ceiling .Originally, trapdoors were sack traps in mills, and allowed the sacks to pass up through the mill while naturally falling back to a closed position....

    is a door that is oriented horizontally in a floor
    Floor
    A floor is the walking surface of a room or vehicle. Floors vary from simple dirt in a cave to many-layered surfaces using modern technology...

     or ceiling
    Ceiling
    A ceiling is an overhead interior surface that covers the upper limit of a room. It is generally not a structural element, but a finished surface concealing the underside of the floor or roof structure above....

    , often accessed via a ladder
    Ladder
    A ladder is a vertical or inclined set of rungs or steps. There are two types: rigid ladders that can be leaned against a vertical surface such as a wall, and rope ladders that are hung from the top. The vertical members of a rigid ladder are called stringers or stiles . Rigid ladders are usually...

    .
  • Blast-proof doors are constructed to allow access to a structure but also to provide protection from the force of explosions.
  • A garden door is any door that opens to a garden
    Garden
    A garden is a planned space, usually outdoors, set aside for the display, cultivation, and enjoyment of plants and other forms of nature. The garden can incorporate both natural and man-made materials. The most common form today is known as a residential garden, but the term garden has...

     or backyard. It is often used specifically for double French doors in place of a sliding glass door
    Sliding glass door
    A Sliding glass door or Patio door, a type of sliding door in architecture and construction, is a large glass window opening in a structure that provide door access from a room to the outdoors, fresh air, and copious natural light. A sliding glass door is usually considered a single unit consisting...

     (also known as Patio doors). In such a configuration, it has the advantage of a very large opening for moving large objects in and out.
  • A pet door (also known as a dog door or cat flap) is an opening in a door to allow pet
    Pet
    A pet is a household animal kept for companionship and a person's enjoyment, as opposed to wild animals or to livestock, laboratory animals, working animals or sport animals, which are kept for economic or productive reasons. The most popular pets are noted for their loyal or playful...

    s to enter and exit without the main door being opened. It may be simply covered by a rubber
    Rubber
    Natural rubber, also called India rubber or caoutchouc, is an elastomer that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined...

     flap or it may be an actual door hinged on the top that the pet can push through. Pet doors may be mounted in a sliding glass door as a new (permanent or temporary) panel. Pet doors may be unidirectional, only allowing pets to exit. Pet doors may be electronic, only allowing pets with a special electronic tag to enter.


Design and styles

Many kinds of doors have specific names, depending on their purpose. The most common variety of door is the single-leaf door which consists of a single rigid panel that fills the doorway. Many variations on this basic design are possible, such as the double-leaf door or double doors and French doors that have two adjacent independent panels hinged on each side of the doorway.

A half door or Dutch door
Dutch door
A Dutch door , or stable door , or half door , is a door divided horizontally in such a fashion that the bottom half may remain shut while the top half opens...

or stable door is divided in half horizontally. Traditionally the top half can be opened to allow a horse
Horse
The horse is one of two extant subspecies of Equus ferus, or the wild horse. It is a single-hooved mammal belonging to the taxonomic family Equidae. The horse has evolved over the past 45 to 55 million years from a small multi-toed creature into the large, single-toed animal of today...

 or other animal
Animal
Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...

 to be fed, while the bottom half remained closed to keep the animal inside. This style of door has been adapted for homes.

Saloon doors are a pair of lightweight swing doors often found in public
Public
In public relations and communication science, publics are groups of individuals, and the public is the totality of such groupings. This is a different concept to the sociological concept of the Öffentlichkeit or public sphere. The concept of a public has also been defined in political science,...

 bars, and especially associated with the American west. Saloon doors, also known as cafe
Café
A café , also spelled cafe, in most countries refers to an establishment which focuses on serving coffee, like an American coffeehouse. In the United States, it may refer to an informal restaurant, offering a range of hot meals and made-to-order sandwiches...

 doors
, often use bidirectional hinge
Hinge
A hinge is a type of bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation. Hinges may be made of flexible material or of moving components...

s which close the door regardless of which direction it is opened by incorporating springs
Spring (device)
A spring is an elastic object used to store mechanical energy. Springs are usually made out of spring steel. Small springs can be wound from pre-hardened stock, while larger ones are made from annealed steel and hardened after fabrication...

. Saloon doors that only extend from knee
Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...

-level to chest
Chest
The chest is a part of the anatomy of humans and various other animals. It is sometimes referred to as the thorax or the bosom.-Chest anatomy - Humans and other hominids:...

-level are known as batwing doors.

A blind door or Gibb door is a door with no visible trim or operable components. It is designed to blend with the adjacent wall in all finishes, and visually to be a part of the wall, a disguise
Disguise
A disguise can be anything which conceals or changes a person's physical appearance, including a wig, glasses, makeup, costume or other ways. Camouflage is one type of disguise for people, animals and objects...

d door.

A barn door is a door characteristic of a barn. They are often/always found on barns, and because of a barn's immense size (often) doors are subsequently big for utility.

A French door is a door (installed singly or as one of a matching pair or series) consisting of a frame around one or more transparent and/or translucent panels (called lights or lites); it is also called a French window as it resembles a door-height casement window. A pair of French doors does not generally include a central mullion (as do some casement window pairs), thus allowing a wider unobstructed opening. The frame typically requires a weather strip at floor level and where the doors meet to prevent water ingress. An espagnolette
Espagnolette
An espagnolette is a locking device, normally mounted on the vertical frame of a French door or casement window. A handle or knob is connected to a metal rod mounted to the surface of the frame, at about three or four feet above the floor. Operating the handle rotates the rod, which has hooks at...

 bolt allows the head and foot of each door to be secured in one movement. The slender window joinery maximizes light though into the room and minimizes the visual impact of the doorway joinery when considered externally.

A louvred door has fixed or movable wooden fins (often called slats or louver
Louver
A louver or louvre , from the French l'ouvert; "the open one") is a window, blind or shutter with horizontal slats that are angled to admit light and air, but to keep out rain, direct sunshine, and noise...

s) which permit open ventilation while preserving privacy and preventing the passage of light to the interior. Being relatively weak structures, they are most commonly used for wardrobe
Wardrobe
A Wardrobe is a cabinet used for storing clothes.Wardrobe may also refer to:* Wardrobe , a full set of multiple clothing items* Wardrobe , part of royal administration in medieval England...

s and drying rooms, where security is of less importance than good ventilation, although a very similar structure is commonly used to form window shutter
Window shutter
A window shutter is a solid and stable window covering usually consisting of a frame of vertical stiles and horizontal rails...

s.

A composite door is a single leaf door that can be solid or with glass, and is usually filled with high density foam. Most composite doors carry Secured by Design accreditation and PAS 23 and PAS 24.

A flush door is a completely smooth door, having plywood
Plywood
Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...

 or MDF
Medium-density fibreboard
Medium-density fiberboard is an engineered wood product formed by breaking down hardwood or softwood residuals into wood fibres, often in a defibrator, combining it with wax and a resin binder, and forming panels by applying high temperature and pressure...

 fixed over a light timber frame, the hollow parts of which are often filled with a cardboard core material. Skins can also be made out of hardboards, the first of which was invented by William H Mason in 1924. Called Masonite
Masonite
Masonite is a type of hardboard invented by William H. Mason.-History:Masonite was invented in 1924 in Laurel, Mississippi, by William H. Mason. Mass production started in 1929. In the 1930s and 1940s Masonite was used for many applications including doors, roofing, walls, desktops, and canoes...

, its construction involved pressing and steaming wood chips into boards. Flush doors are most commonly employed in the interior of a dwelling, although slightly more substantial versions are occasionally used as exterior doors, especially within hotels and other buildings containing many independent dwellings.

A moulded door has the same structure as that of flush door. The only difference is that the surface material is a moulded skin made of MDF. Skins can also be made out of hardboards, the first of which was invented by William H Mason in 1924. Called Masonite
Masonite
Masonite is a type of hardboard invented by William H. Mason.-History:Masonite was invented in 1924 in Laurel, Mississippi, by William H. Mason. Mass production started in 1929. In the 1930s and 1940s Masonite was used for many applications including doors, roofing, walls, desktops, and canoes...

, its construction involved pressing and steaming wood chips into boards. Molded doors are commonly used as interior doors.

A ledge and brace door is a door made from multiple vertical planks fixed together by two horizontal planks (the ledges) and kept square by a diagonal plank (the brace).

A wicket door
Wicket gate
A wicket gate is a small gate or door, particularly one built into a larger one. The cricket term "wicket" comes from this usage. The term wicket gate is also used in English to refer to automatic ticket barriers or older staffed ticket gates on Japan's railway network...

is a pedestrian door built into a much larger door allowing access without requiring the opening of the larger door. Examples might be found on the ceremonial door of a cathedral or in a large vehicle door in a garage or hangar.

A bifold door is a door unit that has several sections, folding in pairs. Wood is the most common material, and doors may also be metal or glass. Bifolds are most commonly made for closet
Closet
A closet is a small and enclosed space, a cabinet, or a cupboard in a house or building used for general storage or hanging clothes. A closet for food storage is usually referred to as a pantry...

s, but may also be used as units between rooms.

A sliding glass door
Sliding glass door
A Sliding glass door or Patio door, a type of sliding door in architecture and construction, is a large glass window opening in a structure that provide door access from a room to the outdoors, fresh air, and copious natural light. A sliding glass door is usually considered a single unit consisting...

, sometimes called an Arcadia door or a Patio door, is a door made of glass
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...

 that slides open and sometimes has a screen (a removable metal mesh that covers the door).

Australian doors are a pair of plywood swinging doors often found in Australian public houses. These doors are generally red or brown in color and bear a resemblance to the more formal doors found in other British Colonies' public houses.

A false door is a wall decoration that looks like a door. In ancient Egyptian architecture, this was a common element in a tomb, the false door representing a gate to the afterlife. They can also be found in the funerary architecture of the desert tribes (e.g., Libya
Libya
Libya is an African country in the Maghreb region of North Africa bordered by the Mediterranean Sea to the north, Egypt to the east, Sudan to the southeast, Chad and Niger to the south, and Algeria and Tunisia to the west....

n Ghirza).

Types of mechanism

Hinged doors

Most doors are hinge
Hinge
A hinge is a type of bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation. Hinges may be made of flexible material or of moving components...

d along one side to allow the door to pivot away from the doorway in one direction but not in the other. The axis of rotation is usually vertical. In some cases, such as hinged garage door
Garage door
A garage door is a large door on a garage that can either be opened manually or by a garage door opener. Garage doors are necessarily large to allow passage of automobiles and/or trucks.-Description:...

s, the axis may be horizontal, above the door opening.

Doors can be hinged so that the axis of rotation is not in the plane of the door to reduce the space required on the side to which the door opens. This requires a mechanism so that the axis of rotation is on the side other than that in which the door opens. This is sometimes the case in trains, such as for the door to the toilet, which opens inward.

A swing door has special hinges that allow it to open either outwards or inwards, and is usually sprung to keep it closed.

A selfbolting door
Selfbolting door
A selfbolting door is called as such because of its special hinges that permit the panel leaf to move laterally so that the door itself becomes a giant bolt for better security result...

is called as such because of its special hinges that permit the panel leaf to move laterally so that the door itself becomes a giant bolt for better security result. The selfbolting door principle can be used both for hinged doors as for rotating doors, as well as up-and-over doors (in the latter case, the bolts are then placed at top and bottom rather than at the sides).

French doors are derived from an original French design called the casement door. It is basically a double-leaved door with large glass panels in each door leaf, and in which the doors can swing both out as well as in. French doors traditionally have a moulded panel at the bottom of the door.

Dutch door or stable door; the top half of the door operates independently from the bottom half.

Garden door Similar to a French door; the hinge is next to the adjacent fixed door and the latch is located at the wall opening jamb. Typically only one door is operable. More secure than the French door.

Sliding doors

It is often useful to have doors which slide along tracks, often for space or aesthetic considerations.

A bypass door is a door unit that has two or more sections. The doors can slide in either direction along one axis on parallel overhead tracks, sliding past each other. They are most commonly used in closets, in order to access one side of the closet at a time. The doors in a bypass unit will overlap slightly when viewed from the front, in order not to have a visible gap between them.

Doors which slide between two wall panels are called pocket door
Pocket door
A pocket door is a sliding door that disappears, when fully open, into a compartment in the adjacent wall. Pocket doors are used for architectural effect, or when there is no room for the swing of a hinged door. They usually travel on rollers suspended from an overhead track, although some also...

s
.

Sliding glass doors are common in many houses, particularly as an entrance to the backyard. Such doors are also popular for use for the entrances to commercial structures.

Rotating doors

A revolving door
Revolving door
A revolving door typically consists of three or four doors that hang on a center shaft and rotate around a vertical axis within a cylindrical enclosure. Revolving doors are energy efficient as they prevent drafts, thus preventing increases in the heating or cooling required for the building...

normally has four wings/leaves that hang on a center shaft and rotate one way about a vertical axis. The door may be motorized, or pushed manually using pushbars. People can walk out of and into the building at the same time. Between the point of access and the point of exit the user walks through an airlock. Revolving doors therefore create a good seal from the outside and help to reduce A/C
Air conditioning
An air conditioner is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area. The cooling is done using a simple refrigeration cycle...

 and heating costs climate control from the building. This type of door is also often seen as a mark of prestige
Prestige (sociology)
Prestige is a word commonly used to describe reputation or esteem, though it has three somewhat related meanings that, to some degree, may be contradictory. Which meaning applies depends on the historical context and the person using the word....

 and glamour for a building and it not unusual for neighbouring buildings to install their own revolving doors when a rival building gets one.

A butterfly door called because of its two "wings". It consists of a double-wide panel with its rotation axle in the centre, effectively creating two separate openings when the door is opened. Butterfly doors are made to rotate open in one direction (usually counterclockwise), and rotate closed in the opposite direction. The door is not equipped with handles, so it is a "push" door. This is for safety, because if it could open in both directions, someone approaching the door might be caught off-guard by someone else opening the other side, thus impacting the first person. Such doors are popular in public transit stations, as it has a large capacity, and when the door is opened, traffic passing in both directions keeps the door open. They are particularly popular in underground subway stations, because they are heavy, and when air currents are created by the movement of trains, the force will be applied to both wings of the door, thus equalizing the force on either side, keeping the door shut.

Others

Up-and-over or overhead doors are often used in garages. Instead of hinges it has a mechanism, often counterbalanced or sprung
Torsion spring
A torsion spring is a spring that works by torsion or twisting; that is, a flexible elastic object that stores mechanical energy when it is twisted. The amount of force it exerts is proportional to the amount it is twisted. There are two types...

, that allows it to be lifted so that it rests horizontally above the opening. A roller shutter
Roller shutter
A roller shutter, roller door or sectional overhead door is a type of door or window shutter consisting of many horizontal slats hinged together. The door is raised to open it and lowered to close it. On large doors, the action may be motorized. It provides protection against wind and rain...

 or sectional overhead door is one variant of this type.

A tambour door is an up-and-over door made of narrow horizontal slats and "rolls" up and down by sliding along vertical tracks and is typically found in entertainment centres and cabinets.

Automatically opening doors are powered open and closed either by electricity, spring, or both. There are several methods by which an automatically opening door is activated:
  1. A sensor
    Sensor
    A sensor is a device that measures a physical quantity and converts it into a signal which can be read by an observer or by an instrument. For example, a mercury-in-glass thermometer converts the measured temperature into expansion and contraction of a liquid which can be read on a calibrated...

     detects traffic is approaching. Sensors for automatic doors are generally:
    • A pressure sensor
      Pressure sensor
      A pressure sensor measures pressure, typically of gases or liquids. Pressure is an expression of the force required to stop a fluid from expanding, and is usually stated in terms of force per unit area. A pressure sensor usually acts as a transducer; it generates a signal as a function of the...

       - e.g., a floor mat which reacts to the pressure of someone standing on it.
    • An infrared
      Infrared
      Infrared light is electromagnetic radiation with a wavelength longer than that of visible light, measured from the nominal edge of visible red light at 0.74 micrometres , and extending conventionally to 300 µm...

       curtain
      Curtain
      A curtain is a piece of cloth intended to block or obscure light, or drafts, or water in the case of a shower curtain. Curtains hung over a doorway are known as portières...

       or beam which shines invisible light onto sensors; if someone or something blocks the beam the door is triggered open.
    • A motion sensor which uses low-power microwave radar
      Radar
      Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...

       for the same effect.
    • A remote sensor (e.g. based on infrared or radio waves) can be triggered by a portable remote control
      Remote control
      A remote control is a component of an electronics device, most commonly a television set, used for operating the television device wirelessly from a short line-of-sight distance.The remote control is usually contracted to remote...

      , or is installed inside a vehicle. These are popular for garage doors.
  2. A switch
    Switch
    In electronics, a switch is an electrical component that can break an electrical circuit, interrupting the current or diverting it from one conductor to another....

     is operated manually, perhaps after security checks. This can be a push button switch or a swipe card.
  3. The act of pushing or pulling the door triggers the open and close cycle. These are also known as power-assisted doors.


In addition to activation sensors automatically opening doors are generally fitted with safety sensors. These are usually an infrared curtain or beam, but can be a pressure mat fitted on the swing side of the door. The purpose of the safety sensor is to prevent the door from colliding with an object in its path by stopping or slowing its motion.

Inward opening doors are doors that can only be opened (or forced open) from outside a building. Such doors pose a substantial fire risk to occupants of occupied buildings when they are locked. As such doors can only be forced open from the outside, building occupants would be prevented from escaping. In commercial and retail situations manufacturers have included in the design a mechanism that allows an inward opening door to be pushed open outwards in the event of an emergency (which is often a regulatory requirement). This is known as a 'breakaway' feature. Pushing the door outward at its closed position, through a switch mechanism, disconnects power to the latch and allows the door to swing outward. Upon returning the door to the closed position, power is restored.

Rebated doors, a term chiefly used in Britain, are double doors having a lip (i.e. a Rabbet
Rabbet
A rabbet is a recess or groove cut into the edge of a piece of machineable material, usually wood. When viewed in cross-section, a rabbet is two-sided and open to the edge or end of the surface into which it is cut....

) on the vertical edge where they meet.

Door construction and components

Panel doors

Panel doors, also called stile and rail doors, are built with frame and panel
Frame and panel
Frame and panel construction is a woodworking technique often used in the making of doors, wainscoting, and other decorative features for cabinets, furniture, and homes...

 construction:
  • Stile
    Stile
    A stile is a structure which provides people a passage through or over a fence or boundary via steps, ladders, or narrow gaps. Stiles are often built in rural areas or along footpaths to allow access to an adjacent field or area separated by a fence, wall or hedge...

    s - Vertical boards that run the full height of a door and compose its right and left edges. The hinges are mounted to the fixed side (known as the "hanging stile"), and the handle, lock, bolt, and/or latch are mounted on the swinging side (known as the "latch stile").
  • Rails
    Frame and panel
    Frame and panel construction is a woodworking technique often used in the making of doors, wainscoting, and other decorative features for cabinets, furniture, and homes...

     - Horizontal boards at the top, bottom, and optionally in the middle of a door that join the two stiles and split the door into two or more rows of panels. The "top rail" and "bottom rail" are named for their positions. The bottom rail is also known as "kick rail". A middle rail at the height of the bolt is known as the "lock rail", other middle rails are commonly known as "cross rails".
  • Mullion
    Mullion
    A mullion is a vertical structural element which divides adjacent window units. The primary purpose of the mullion is as a structural support to an arch or lintel above the window opening. Its secondary purpose may be as a rigid support to the glazing of the window...

    s - Smaller optional vertical boards that run between two rails, and split the door into two or more columns of panels, the term is used sometimes for verticals in doors, but more often (UK and Australia) it refers to verticals in windows.
  • Muntin - Optional vertical members that divide the door into smaller panels.
  • Panels - Large, wider boards used to fill the space between the stiles, rails, and mullions. The panels typically fit into grooves in the other pieces, and help to keep the door rigid. Panels may be flat, or in raised panel designs.
  • Light or Lite - a piece of glass used in place of a panel, essentially giving the door a window.

Plank and batten doors

Plank and batten doors are an older design consisting primarily of vertical slats:
  • Planks - Vertical boards that extend the full height of the door, and are placed side by side filling the door's width.
  • Batten
    Batten
    A batten is a thin strip of solid material, typically made from wood, plastic or metal. Battens are used in building construction and various other fields as both structural and purely cosmetic elements...

    s - Smaller slats that extend horizontally across the door which the planks are affixed to. The battens hold the planks together. Sometimes a long diagonal slat or two are also implemented to prevent the door from skewing. On some doors, especially antique ones, the battens are replaced with iron bars that are often built into the hinges as extensions of the door-side plates.

Ledged and braced doors

This type consists of vertical tongue and grooved boards held together with battens and diagonal braces.

Impact-Resistant doors

Impact Resistant doors have rounded stile edges to dissipate energy and minimize edge chipping, scratching and denting. The formed edges are often made of an engineered material such as Acrovyn. Impact-resistant doors excel in high traffic areas such as hospitals, schools, and hotels.

Frame and filled doors

This type consists of a solid timber frame, filled on one face, face with Tongue and Grooved boards. Quite often used externally with the boards on the weather face.

Flush doors

Many modern doors, including most interior doors, are flush doors:
  • Stile
    Stile
    A stile is a structure which provides people a passage through or over a fence or boundary via steps, ladders, or narrow gaps. Stiles are often built in rural areas or along footpaths to allow access to an adjacent field or area separated by a fence, wall or hedge...

    s and rails
    Frame and panel
    Frame and panel construction is a woodworking technique often used in the making of doors, wainscoting, and other decorative features for cabinets, furniture, and homes...

     - As above, but usually smaller. They form the outside edges of the door.
  • Core material: Material within the door used simply to fill space, provide rigidity and reduce druminess.
    • Hollow-core - Often consists of a lattice
      Square lattice
      In mathematics, the square lattice is a type of lattice in a two-dimensional Euclidean space. It is the two-dimensional version of the integer lattice. It is one of the five types of two-dimensional lattices as classified by their symmetry groups; its symmetry group is known symbolically as p4m.Two...

       or honeycomb
      Hexagonal lattice
      The hexagonal lattice or equilateral triangular lattice is one of the five 2D lattice types.Three nearby points form an equilateral triangle. In images four orientations of such a triangle are by far the most common...

       made of corrugated cardboard, or thin wooden slats. Can also be built with staggered wooden blocks. Hollow-core flush doors are commonly used as interior doors.
      • Lock block - A solid block of wood mounted within a hollow-core flush door near the bolt to provide a solid and stable location for mounting the door's hardware.
    • Stave-core - Consists of wooden slats stacked upon one another in a manner similar to a plank & batten door (though the slats are usually thinner) or the wooden-block hollow-core (except that the space is entirely filled).
    • Solid-core - Can consist of low-density particle board
      Particle board
      Particle board, or particleboard , is an engineered wood product manufactured from wood particles, such as wood chips, sawmill shavings, or even saw dust, and a synthetic resin or other suitable binder, which is pressed and extruded...

       or foam
      Foam
      -Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...

       used to completely fill the space within the door. Solid-core flush doors (especially foam-core ones) are commonly used as exterior doors because they provide more insulation
      Thermal insulation
      Thermal insulation is the reduction of the effects of the various processes of heat transfer between objects in thermal contact or in range of radiative influence. Heat transfer is the transfer of thermal energy between objects of differing temperature...

       and strength.
  • Skin - The front and back faces of the door are then covered with wood veneer
    Wood veneer
    In woodworking, veneer refers to thin slices of wood, usually thinner than 3 mm , that are typically glued onto core panels to produce flat panels such as doors, tops and panels for cabinets, parquet floors and parts of furniture. They are also used in marquetry...

    , thin plywood
    Plywood
    Plywood is a type of manufactured timber made from thin sheets of wood veneer. It is one of the most widely used wood products. It is flexible, inexpensive, workable, re-usable, and can usually be locally manufactured...

    , sheet metal
    Sheet metal
    Sheet metal is simply metal formed into thin and flat pieces. It is one of the fundamental forms used in metalworking, and can be cut and bent into a variety of different shapes. Countless everyday objects are constructed of the material...

    , fiberglass
    Fiberglass
    Glass fiber is a material consisting of numerous extremely fine fibers of glass.Glassmakers throughout history have experimented with glass fibers, but mass manufacture of glass fiber was only made possible with the invention of finer machine tooling...

    , or vinyl
    Vinyl
    A vinyl compound is any organic compound that contains a vinyl group ,which are derivatives of ethene, CH2=CH2, with one hydrogen atom replaced with some other group...

    . The wooden materials are usually layered with the grain alternating direction between layers to prevent warping. Fiberglass and metal-faced doors are sometimes given a layer of cellulose so that they may be stained to look like real wood.

Moulded doors

  • Stile
    Stile
    A stile is a structure which provides people a passage through or over a fence or boundary via steps, ladders, or narrow gaps. Stiles are often built in rural areas or along footpaths to allow access to an adjacent field or area separated by a fence, wall or hedge...

    s and rails
    Frame and panel
    Frame and panel construction is a woodworking technique often used in the making of doors, wainscoting, and other decorative features for cabinets, furniture, and homes...

     - As above, but usually smaller. They form the outside edges of the door.
  • Core material: Material within the door used simply to fill space, provide rigidity and reduce druminess.
    • Hollow-core - Often consists of a lattice
      Square lattice
      In mathematics, the square lattice is a type of lattice in a two-dimensional Euclidean space. It is the two-dimensional version of the integer lattice. It is one of the five types of two-dimensional lattices as classified by their symmetry groups; its symmetry group is known symbolically as p4m.Two...

       or honeycomb
      Hexagonal lattice
      The hexagonal lattice or equilateral triangular lattice is one of the five 2D lattice types.Three nearby points form an equilateral triangle. In images four orientations of such a triangle are by far the most common...

       made of corrugated cardboard, or thin wooden slats. Can also be built with staggered wooden blocks. Hollow-core flush doors are commonly used as interior doors.
      • Lock block - A solid block of wood mounted within a hollow-core flush door near the bolt to provide a solid and stable location for mounting the door's hardware.
    • Stave-core - Consists of wooden slats stacked upon one another in a manner similar to a plank & batten door (though the slats are usually thinner) or the wooden-block hollow-core (except that the space is entirely filled).
    • Solid-core - Can consist of low-density particle board
      Particle board
      Particle board, or particleboard , is an engineered wood product manufactured from wood particles, such as wood chips, sawmill shavings, or even saw dust, and a synthetic resin or other suitable binder, which is pressed and extruded...

       or foam
      Foam
      -Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...

       used to completely fill the space within the door. Solid-core flush doors (especially foam-core ones) are commonly used as exterior doors because they provide more insulation
      Thermal insulation
      Thermal insulation is the reduction of the effects of the various processes of heat transfer between objects in thermal contact or in range of radiative influence. Heat transfer is the transfer of thermal energy between objects of differing temperature...

       and strength.
  • Skin - The front and back faces of the door are covered with HDF / MDF skins.

Swing direction

Door swings
For most of the world, door swings, or handing
Handing
A door's handing describes the direction in which it swings. Doors can be either right or left handed and be "inswinging" or "outswinging".To determine a door's handing, stand facing the closed door on the side of the door that will swing toward you as it is opened. If the door handle is on your...

, are determined while standing on the outside or less secure side of the door while facing the door (i.e., standing on the side you use the key on, going from outside to inside, or from public to private).

It is especially important to get the hand and swing right on exterior doors, as the transom is usually sloped and sealed to resist water entry, and to properly drain. In some custom millwork (or with some master carpenters), the manufacture or installer will bevel the leading edge (the first edge to meet the jamb as the door is closing) so that the door fits tight without binding. Specifying an incorrect hand and/or swing will cause the door to bind, not close properly, or leak (for exterior doors). Fixing this specification error will be expensive and/or time consuming. See note below for Australia where a different orientation is used.

In North America, many doors now come with factory-installed hinges, pre-hung on the jamb and sills.

To determine hand, stand on the outside (or less secure) side of the door. While facing the door, if the hinge is on the right side of the door, the door is "Right handed"; or if the hinge is on the left, it is "Left handed".

If the door swings toward you, it is "Reverse swing"; or if the door swings away from you, it is "Normal swing".

In other words:
  • Left hand hinge (LHH): Standing outside (or on the less secure side, or on the public side of the door), the hinges are on the left and the door opens in (away from you).
  • Right hand hinge (RHH): Standing outside (or on the less secure side), the hinges are on the right and the door opens in (away from you).
  • Left hand reverse (LHR): Standing outside the house (or on the less secure side), the hinges are on the left, knob on right, on opening the door it swings towards you (i.e. the door swings open towards the outside, or "outswing")
  • Right hand reverse (RHR): Standing outside the house (i.e. on the less secure side), the hinges are on the right, knob on left, opening the door by pulling the door towards you (i.e. open swings to the outside, or "outswing")


Note: In Australia, this is different. The refrigerator rule applies (you can't stand in a fridge, the door always opens towards you) - If the hinges are on the left then its a left hand (or left hung) door. If the hinges are on the right then its a right hand (or right hung) door.
See the Australian Standards for Installation of Timber Doorsets, AS 1909-1984 pg 6.

In public buildings, exterior doors should open to the outside in order to comply with any fire codes that may be in force in that jurisdiction. If the door opens inward and there is a fire, there can be a crush of people who run for the door and they will not be able to open it.

Dimensions

A standard US residential door size is 36" x 80" (0.91 m x 2.03 m).

Exterior and passage (room to room) doors: Standard door sizes in the US are from 2'-6" to 3'-0" wide, increasing in 2" increments. Most residential interior doors are 2'-6" wide except when designed to allow wheelchair access, then 3'-0". Residential doors are often 6'-8' high, as are many small stores, offices, and other light commercial buildings. Larger commercial, public buildings and grand homes often use doors of greater height. Older buildings often have smaller doors.

Closets: small spaces such as closets, dressing rooms, half-baths, storage rooms, cellars, etc. often are accessed through doors smaller than passage doors in one or both dimensions but similar in design.

Garages: Garage doors are generally 7'-0" or 8'-0" wide for a single-car opening.

Doorway components

When framed in wood for snug fitting of a door, the doorway consists of two vertical jambs on either side, a lintel or head jamb at the top, and perhaps a threshold at the bottom. When a door has more than one movable section, one of the sections may be called a leaf. See door furniture
Door furniture
Door furniture or Door hardware refers to any of the items that are attached to a door or a drawer to enhance its functionality or appearance....

 for a discussion of attachments to doors such as door handle
Door handle
A door handle is an attached mechanism used to open or close a door. In the United States, door handle can refer to any fixed or lever-operated door latch device, including on car doors. The term door knob tends to refer to round operating mechanisms.-History:The first documented invention of the...

s and doorknobs.
  • Lintel - A horizontal beam above a door that supports the wall above it. (Also known as a header)
  • Jambs - The vertical posts that form the sides of a door frame, where the hinges are mounted, and with which the bolt interacts.
  • Sill
    Sill plate
    A sill plate or sole plate in construction and architecture is the bottom horizontal member of a wall or building to which vertical members are attached. Sill plates are usually composed of lumber. It usually comes in sizes of 2×4, 2×6, 2×8, and 2×10. In the platform framing method the sill plate...

     - A horizontal beam below the door that supports the frame
  • Doorstop
    Doorstop
    A doorstop is an object or device used to hold a door open or closed, or to prevent a door from opening too widely...

     - a thin slat built inside the frame to prevent a door from swinging through when closed, which might break the hinges.
  • Architrave
    Architrave
    An architrave is the lintel or beam that rests on the capitals of the columns. It is an architectural element in Classical architecture.-Classical architecture:...

     - The decorative molding
    Molding (decorative)
    Molding or moulding is a strip of material with various profiles used to cover transitions between surfaces or for decoration. It is traditionally made from solid milled wood or plaster but may be made from plastic or reformed wood...

     that outlines a door frame. (called an Archivolt
    Archivolt
    An archivolt is an ornamental molding or band following the curve on the underside of an arch. It is composed of bands of ornamental moldings surrounding an arched opening, corresponding to the architrave in the case of a rectangular opening...

     if the door is arched). Called door casing or brickmold in North America.

Related hardware

Door furniture or hardware refers to any of the items that are attached to a door or a drawer to enhance its functionality or appearance. This includes items such as hinges, handles, door stops, etc.

History

The earliest records are those represented in the paintings of the Egyptian
Ancient Egypt
Ancient Egypt was an ancient civilization of Northeastern Africa, concentrated along the lower reaches of the Nile River in what is now the modern country of Egypt. Egyptian civilization coalesced around 3150 BC with the political unification of Upper and Lower Egypt under the first pharaoh...

 tombs, in which they are shown as single or double doors, each in a single piece of wood. In Egypt, where the climate is intensely dry, there would be no fear of their warping, but in other countries it would be necessary to frame them, which according to Vitruvius
Vitruvius
Marcus Vitruvius Pollio was a Roman writer, architect and engineer, active in the 1st century BC. He is best known as the author of the multi-volume work De Architectura ....

 (iv. 6.) was done with stiles (sea/si) and rails (see: Frame and panel
Frame and panel
Frame and panel construction is a woodworking technique often used in the making of doors, wainscoting, and other decorative features for cabinets, furniture, and homes...

): the spaces enclosed being filled with panels (tympana) let into grooves made in the stiles and rails. The stiles were the vertical boards, one of which, tenoned
Mortise and tenon
The mortise and tenon joint has been used for thousands of years by woodworkers around the world to join pieces of wood, mainly when the adjoining pieces connect at an angle of 90°. In its basic form it is both simple and strong. Although there are many joint variations, the basic mortise and tenon...

 or hinge
Hinge
A hinge is a type of bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation. Hinges may be made of flexible material or of moving components...

d, is known as the hanging stile, the other as the middle or meeting stile. The horizontal cross pieces are the top rail, bottom rail, and middle or intermediate rails. The most ancient doors were in timber, those made for King Solomon's temple
Solomon's Temple
Solomon's Temple, also known as the First Temple, was the main temple in ancient Jerusalem, on the Temple Mount , before its destruction by Nebuchadnezzar II after the Siege of Jerusalem of 587 BCE....

 being in olive wood (I Kings vi. 31-35), which were carved and overlaid with gold. The doors dwelt upon in Homer
Homer
In the Western classical tradition Homer , is the author of the Iliad and the Odyssey, and is revered as the greatest ancient Greek epic poet. These epics lie at the beginning of the Western canon of literature, and have had an enormous influence on the history of literature.When he lived is...

 would appear to have been cased in silver or brass. Besides Olive wood, elm, cedar, oak and cypress were used. A 5,000-year-old door has been found by archaeologists in Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....

.

All ancient doors were hung by pivots at the top and bottom of the hanging stile which worked in sockets in the lintel and sill
Sill plate
A sill plate or sole plate in construction and architecture is the bottom horizontal member of a wall or building to which vertical members are attached. Sill plates are usually composed of lumber. It usually comes in sizes of 2×4, 2×6, 2×8, and 2×10. In the platform framing method the sill plate...

, the latter being always in some hard stone such as basalt
Basalt
Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

 or granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...

. Those found at Nippur
Nippur
Nippur was one of the most ancient of all the Sumerian cities. It was the special seat of the worship of the Sumerian god Enlil, the "Lord Wind," ruler of the cosmos subject to An alone...

 by Dr. Hilprecht, dating from 2000 B.C. were in dolerite. The tenons of the gate
Gate
A gate is a point of entry to a space enclosed by walls, or a moderately sized opening in a fence. Gates may prevent or control entry or exit, or they may be merely decorative. Other terms for gate include yett and port...

s at Balawat
Balawat
Balawat is a historical location in Ninawa Governorate, Iraq, southeast from the city of Mosul and to the south of the modern Assyrian town of Bakhdida. It was the site of the ancient Neo-Assyrian city of Imgur-Enlil...

 were sheathed with bronze (now in the British Museum
British Museum
The British Museum is a museum of human history and culture in London. Its collections, which number more than seven million objects, are amongst the largest and most comprehensive in the world and originate from all continents, illustrating and documenting the story of human culture from its...

). These doors or gates were hung in two leaves, each about 8 in 4 in (2.54 m) wide and 27 ft (8.2 m). high; they were encased with bronze bands or strips, 10 in. high, covered with repouss decoration of figures, etc. The wood doors would seem to have been about 3 in. thick, but the hanging stile was over 14 inches (355.6 mm) diameter. Other sheathings of various sizes in bronze have been found, which proves this to have been the universal method adopted to protect the wood pivots. In the Hauran
Hauran
Hauran, , also spelled Hawran or Houran, is a volcanic plateau, a geographic area and a people located in southwestern Syria and extending into the northwestern corner of Jordan. It gets its name from the Aramaic Hawran, meaning "cave land." In geographic and geomorphic terms, its boundaries...

 in Syria, where timber is scarce the doors were made in stone, and one measuring 5 in 4 in (1.63 m) by 2 in 7 in (0.7874 m) is in the British Museum; the band on the meeting stile shows that it was one of the leaves of a double door. At Kuffeir near Bostra in Syria, Burckhardt found stone doors, 9 to 10 ft (3 m). high, being the entrance doors of the town. In Etruria
Etruria
Etruria—usually referred to in Greek and Latin source texts as Tyrrhenia—was a region of Central Italy, an area that covered part of what now are Tuscany, Latium, Emilia-Romagna, and Umbria. A particularly noteworthy work dealing with Etruscan locations is D. H...

 many stone doors are referred to by Dennis.

The ancient Greek
Ancient Greece
Ancient Greece is a civilization belonging to a period of Greek history that lasted from the Archaic period of the 8th to 6th centuries BC to the end of antiquity. Immediately following this period was the beginning of the Early Middle Ages and the Byzantine era. Included in Ancient Greece is the...

 and Roman
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....

 doors were either single doors, double doors, sliding door
Sliding door
A sliding door is a type of door which opens horizontally by sliding, whereby the door is either mounted on or suspended from a track. Types of sliding doors include pocket doors, Arcadia doors, and bypass doors...

s or folding door
Folding door
A folding door is a type of door which opens by folding back in sections. They are usually to be found indoors. Folding doors were already known by the Romans as excavations in Pompeii have revealed....

s, in the last case the leaves were hinged and folded back. In Eumachia
Eumachia
Eumachia was the public priestess of Venus in Pompeii during the middle of the 1st century AD as well as the matron of the Concordia Augustus. The Concordia Augustus was an imperial cult initiated by Livia, widow of Augustus, dedicated to the Divus Augustus, the deified emperor Augustus.- Family...

, is a painting of a door with three leaves. In the tomb of Theron at Agrigentum there is a single four-panel door carved in stone. In the Blundell collection is a bas-relief of a temple with double doors, each leaf with five panels. Among existing examples, the bronze doors in the church of SS. Cosmas and Damiano
Santi Cosma e Damiano
The basilica of Santi Cosma e Damiano is a church in Rome, Italy, located in the Roman Forum. It is one of the ancient churches called tituli, of which cardinals are patrons as deacons: the Cardinal Deacon of the Titulus Ss. Cosmae et Damiani is Giovanni Cheli...

, in Rome, are important examples of Roman metal work of the best period; they are in two leaves, each with two panels, and are framed in bronze. Those of the Pantheon
Pantheon, Rome
The Pantheon ,Rarely Pantheum. This appears in Pliny's Natural History in describing this edifice: Agrippae Pantheum decoravit Diogenes Atheniensis; in columnis templi eius Caryatides probantur inter pauca operum, sicut in fastigio posita signa, sed propter altitudinem loci minus celebrata.from ,...

 are similar in design, with narrow horizontal panels in addition, at the top, bottom and middle. Two other bronze doors of the Roman period are in the Lateran Basilica
Basilica of St. John Lateran
The Papal Archbasilica of St. John Lateran , commonly known as St. John Lateran's Archbasilica and St. John Lateran's Basilica, is the cathedral of the Diocese of Rome and the official ecclesiastical seat of the Bishop of Rome, who is the Pope...

.

The Greek scholar Heron of Alexandria created the earliest known automatic door in the 1st century CE
Common Era
Common Era ,abbreviated as CE, is an alternative designation for the calendar era originally introduced by Dionysius Exiguus in the 6th century, traditionally identified with Anno Domini .Dates before the year 1 CE are indicated by the usage of BCE, short for Before the Common Era Common Era...

 during the era of Roman Egypt. The first foot-sensor-activated automatic door was made in China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 during the reign of Emperor Yang of Sui
Emperor Yang of Sui
Emperor Yang of Sui , personal name Yang Guang , alternative name Ying , nickname Amo , known as Emperor Ming during the brief reign of his grandson Yang Tong), was the second son of Emperor Wen of Sui, and the second emperor of China's Sui Dynasty.Emperor Yang's original name was Yang Ying, but...

 (r. 604–618), who had one installed for his royal library. The first automatic gate operator
Gate operator
A gate operator is a mechanical device used to open and close a gate, such as one at the end of a driveway. There are two main types of electric gate openers hydraulic or electromechanical; these can be further slit into the following categories, worm driven, arm openers and underground openers...

s were later created in 1206 by the Arabic inventor
Inventions in the Islamic world
A number of inventions were developed in the medieval Islamic world, a geopolitical region that has at various times extended from Spain and Africa in the west to the Indian subcontinent in the east. The inventions listed here were developed during the medieval Islamic world, which covers the...

, Al-Jazari
Al-Jazari
Abū al-'Iz Ibn Ismā'īl ibn al-Razāz al-Jazarī was a Muslim polymath: a scholar, inventor, mechanical engineer, craftsman, artist, mathematician and astronomer from Al-Jazira, Mesopotamia, who lived during the Islamic Golden Age...

.

The doors of the church of the Nativity
Church of the Nativity
The Church of the Nativity in Bethlehem is one of the oldest continuously operating churches in the world. The structure is built over the cave that tradition marks as the birthplace of Jesus of Nazareth, and thus it is considered sacred by Christians...

 at Bethlehem
Bethlehem
Bethlehem is a Palestinian city in the central West Bank of the Jordan River, near Israel and approximately south of Jerusalem, with a population of about 30,000 people. It is the capital of the Bethlehem Governorate of the Palestinian National Authority and a hub of Palestinian culture and tourism...

 (6th century) are covered with plates of bronze, cut out in patterns:
those of Hagia Sophia
Hagia Sophia
Hagia Sophia is a former Orthodox patriarchal basilica, later a mosque, and now a museum in Istanbul, Turkey...

 at Constantinople
Constantinople
Constantinople was the capital of the Roman, Eastern Roman, Byzantine, Latin, and Ottoman Empires. Throughout most of the Middle Ages, Constantinople was Europe's largest and wealthiest city.-Names:...

, of the 8th and 9th century, are wrought in bronze, and the west doors of the cathedral of Aix-la-Chapelle
Aachen
Aachen has historically been a spa town in North Rhine-Westphalia, Germany. Aachen was a favoured residence of Charlemagne, and the place of coronation of the Kings of Germany. Geographically, Aachen is the westernmost town of Germany, located along its borders with Belgium and the Netherlands, ...

 (9th century), of similar manufacture, were probably brought from Constantinople, as also some of those in St. Marks, Venice
St Mark's Basilica
The Patriarchal Cathedral Basilica of Saint Mark is the cathedral church of the Roman Catholic Archdiocese of Venice, northern Italy. It is the most famous of the city's churches and one of the best known examples of Byzantine architecture...

.

Of the 11th and 12th centuries there are numerous examples of bronze doors, the earliest being one at Hildesheim
Hildesheim
Hildesheim is a city in Lower Saxony, Germany. It is located in the district of Hildesheim, about 30 km southeast of Hanover on the banks of the Innerste river, which is a small tributary of the Leine river...

, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...

 (1015). The Hildesheim design affected the concept of Gniezno door
Gniezno Doors
The Gniezno Doors are a pair of bronze doors at the entrance to Gniezno Cathedral in Gniezno, Poland, a Gothic building which the doors pre-date, having been carried over from an earlier building. They are decorated with eighteen scenes in bas-relief from the life of St...

 in Poland. Of others in South Italy and Sicily, the following are the finest: in Sant Andrea, Amalfi
Amalfi
Amalfi is a town and comune in the province of Salerno, in the region of Campania, Italy, on the Gulf of Salerno, c. 35 km southeast of Naples. It lies at the mouth of a deep ravine, at the foot of Monte Cerreto , surrounded by dramatic cliffs and coastal scenery...

 (1060); Salerno
Salerno
Salerno is a city and comune in Campania and is the capital of the province of the same name. It is located on the Gulf of Salerno on the Tyrrhenian Sea....

 (1099); Canosa
Canosa
Canosa di Puglia is a town and comune in Apulia in southern Italy, between Bari and Foggia, located in the province of Barletta-Andria-Trani, not far from the position on the Ofanto River where the Romans found refuge after the defeat of the Battle of Cannae...

 (1111); Troia, two doors (1119 and 1124); Ravello
Ravello
Ravello is a town and comune situated above the Amalfi Coast in the province of Salerno, Campania, southern Italy, with has approximately 2,500 inhabitants. It is a popular tourist destination.-History:...

 (1179), by Barisano of Trani, who also made doors for Trani
Trani
Trani is a seaport of Apulia, southern Italy, on the Adriatic Sea, in the new Province of Barletta-Andria-Trani , and 40 km by railway West-Northwest of Bari.- History :...

 cathedral; and in Monreale
Monreale
Monreale is a town and comune in the province of Palermo, in Sicily, Italy, on the slope of Monte Caputo, overlooking the very fertile valley called "La Conca d'oro" , famed for its orange, olive and almond trees, the produce of which is exported in large quantities...

 and Pisa cathedrals, by Bonano of Pisa. In all these cases the hanging stile had pivots at the top and bottom. The exact period when the hinge was substituted is not quite known, but the change apparently brought about another method of strengthening and decorating doors, viz, with wrought-iron bands of infinite varieties of design. As a rule three bands from which the ornamental work springs constitute the hinges, which have rings outside the hanging stiles fitting on to vertical tenons run into the masonry or wooden frame. There is an early example of the 12th century in Lincoln
Lincoln Cathedral
Lincoln Cathedral is a historic Anglican cathedral in Lincoln in England and seat of the Bishop of Lincoln in the Church of England. It was reputedly the tallest building in the world for 249 years . The central spire collapsed in 1549 and was not rebuilt...

; in France the metal work of the doors of Notre Dame
Notre Dame de Paris
Notre Dame de Paris , also known as Notre Dame Cathedral, is a Gothic, Roman Catholic cathedral on the eastern half of the Île de la Cité in the fourth arrondissement of Paris, France. It is the cathedral of the Catholic Archdiocese of Paris: that is, it is the church that contains the cathedra of...

 at Paris is perhaps the most beautiful in execution, but examples are endless throughout France and England.

Returning to Italy, the most celebrated doors are those of the Battistero di San Giovanni (Florence)
Battistero di San Giovanni (Florence)
The Florence Baptistry or Battistero di San Giovanni is a religious building in Florence , Italy, which has the status of a minor basilica....

, which together with the door frames are all in bronze, the borders of the latter being perhaps the most remarkable: the modeling of the figures, birds and foliage of the south doorway, by Andrea Pisano
Andrea Pisano
Andrea Pisano , also known as Andrea da Pontedera, was an Italian sculptor and architect.-Biography:Andrea Pisano was born at Pontedera, where he also died....

 (1330), and of the east doorway by Ghiberti
Lorenzo Ghiberti
Lorenzo Ghiberti , born Lorenzo di Bartolo, was an Italian artist of the early Renaissance best known for works in sculpture and metalworking.-Early life:...

 (1425–1452), are of great beauty; in the north door (1402–1424) Ghiberti adopted the same scheme of design for the paneling and figure subjects in them as Andrea Pisano, but in the east door the rectangular panels are all filled, with bas-reliefs, in which Scripture subjects are illustrated with innumerable figures, these being probably the gates of Paradise of which Michelangelo
Michelangelo
Michelangelo di Lodovico Buonarroti Simoni , commonly known as Michelangelo, was an Italian Renaissance painter, sculptor, architect, poet, and engineer who exerted an unparalleled influence on the development of Western art...

 speaks.

The doors of the mosques in Cairo
Cairo
Cairo , is the capital of Egypt and the largest city in the Arab world and Africa, and the 16th largest metropolitan area in the world. Nicknamed "The City of a Thousand Minarets" for its preponderance of Islamic architecture, Cairo has long been a centre of the region's political and cultural life...

 were of two kinds; those which, externally, were cased with sheets of bronze or iron, cut out in decorative patterns, and incised or inlaid, with bosses in relief; and those in wood, which were framed with interlaced designs of the square and diamond, this latter description of work being Copt
Copt
The Copts are the native Egyptian Christians , a major ethnoreligious group in Egypt....

ic in its origin. The doors of the palace at Palermo
Palermo
Palermo is a city in Southern Italy, the capital of both the autonomous region of Sicily and the Province of Palermo. The city is noted for its history, culture, architecture and gastronomy, playing an important role throughout much of its existence; it is over 2,700 years old...

, which were made by Saracenic workmen for the Normans
Normans
The Normans were the people who gave their name to Normandy, a region in northern France. They were descended from Norse Viking conquerors of the territory and the native population of Frankish and Gallo-Roman stock...

, are fine examples and in good preservation. A somewhat similar decorative class of door to these latter is found in Verona
Verona
Verona ; German Bern, Dietrichsbern or Welschbern) is a city in the Veneto, northern Italy, with approx. 265,000 inhabitants and one of the seven chef-lieus of the region. It is the second largest city municipality in the region and the third of North-Eastern Italy. The metropolitan area of Verona...

, where the edges of the stiles and rails are beveled and notched.

In the Renaissance period the Italian doors are quite simple, their architects trusting more to the doorways for effect; but in France and Germany the contrary is the case, the doors being elaborately carved, especially in the Louis XIV
Louis XIV of France
Louis XIV , known as Louis the Great or the Sun King , was a Bourbon monarch who ruled as King of France and Navarre. His reign, from 1643 to his death in 1715, began at the age of four and lasted seventy-two years, three months, and eighteen days...

 and Louis XV
Louis XV of France
Louis XV was a Bourbon monarch who ruled as King of France and of Navarre from 1 September 1715 until his death. He succeeded his great-grandfather at the age of five, his first cousin Philippe II, Duke of Orléans, served as Regent of the kingdom until Louis's majority in 1723...

 periods, and sometimes with architectural features such as columns and entablatures with pediment and niches, the doorway being in plain masonry. While in Italy the tendency was to give scale by increasing the number of panels, in France the contrary seems to have been the rule; and one of the great doors at Fontainebleau
Fontainebleau
Fontainebleau is a commune in the metropolitan area of Paris, France. It is located south-southeast of the centre of Paris. Fontainebleau is a sub-prefecture of the Seine-et-Marne department, and it is the seat of the arrondissement of Fontainebleau...

, which is in two leaves, is entirely carried out as if consisting of one great panel only.

The earliest Renaissance
Renaissance
The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...

 doors in France are those of the cathedral of St. Sauveur at Aix
Aix-en-Provence
Aix , or Aix-en-Provence to distinguish it from other cities built over hot springs, is a city-commune in southern France, some north of Marseille. It is in the region of Provence-Alpes-Côte d'Azur, in the département of Bouches-du-Rhône, of which it is a subprefecture. The population of Aix is...

 (1503). In the lower panels there are figures 3 ft (0.9144 m). high in Gothic
Gothic architecture
Gothic architecture is a style of architecture that flourished during the high and late medieval period. It evolved from Romanesque architecture and was succeeded by Renaissance architecture....

 niche
Niche (architecture)
A niche in classical architecture is an exedra or an apse that has been reduced in size, retaining the half-dome heading usual for an apse. Nero's Domus Aurea was the first semi-private dwelling that possessed rooms that were given richly varied floor plans, shaped with niches and exedras;...

s, and in the upper panels a double range of niches with figures about 2 ft (0.6096 m). high with canopies over them, all carved in cedar. The south door of Beauvais Cathedral is in some respects the finest in France; the upper panels are carved in high relief with figure subjects and canopies over them. The doors of the church at Gisors
Gisors
Gisors is a commune in the metropolitan area of Paris, France. It is located northwest from the center of Paris.Gisors, together with the neighbouring communes of Trie-Château and Trie-la-Ville, form an urban area of 12,669 inhabitants...

 (1575) are carved with figures in niches subdivided by classic pilasters superimposed. In St. Maclou at Rouen
Rouen
Rouen , in northern France on the River Seine, is the capital of the Haute-Normandie region and the historic capital city of Normandy. Once one of the largest and most prosperous cities of medieval Europe , it was the seat of the Exchequer of Normandy in the Middle Ages...

 are three magnificently carved doors; those by Jean Goujon have figures in niches on each side, and others in a group of great beauty in the center. The other doors, probably about forty to fifty years later, are enriched with bas-reliefs, landscapes, figures and elaborate interlaced borders.

When it comes to the world's largest door, there is not just one, in fact there are four and they all belong to NASA's Vehicle Assembly Building
Vehicle Assembly Building
The Vehicle Assembly Building, or VAB, at NASA's Kennedy Space Center was used to assemble and house American manned launch vehicles from 1968-2011. It is the fourth largest building in the world by volume...

 at the Kennedy Space Center. The Vehicle Assembly Building was originally built to assembly of Apollo and Saturn vehicles and is now used to support Space Shuttle operations.
Each of the four doors are 139 meters or 456 feet high, in comparison the Statue of Liberty is only 93 meters or 305 feet high.

The oldest door in England can be found in Westminster Abbey
Westminster Abbey
The Collegiate Church of St Peter at Westminster, popularly known as Westminster Abbey, is a large, mainly Gothic church, in the City of Westminster, London, United Kingdom, located just to the west of the Palace of Westminster. It is the traditional place of coronation and burial site for English,...

 and dates from 1050. In England in the 17th century the door panels were raised with bolection
Bolection
A Bolection is a moulding which projects beyond the face of a panel or frame, usually found in panelling, doors and fireplaces, especially when the meeting surfaces are at different levels. See also bilection....

 or projecting moldings, sometimes richly carved, round them; in the 18th century the molding
Molding (decorative)
Molding or moulding is a strip of material with various profiles used to cover transitions between surfaces or for decoration. It is traditionally made from solid milled wood or plaster but may be made from plastic or reformed wood...

s worked on the stile
Stile
A stile is a structure which provides people a passage through or over a fence or boundary via steps, ladders, or narrow gaps. Stiles are often built in rural areas or along footpaths to allow access to an adjacent field or area separated by a fence, wall or hedge...

s and rails
Frame and panel
Frame and panel construction is a woodworking technique often used in the making of doors, wainscoting, and other decorative features for cabinets, furniture, and homes...

 were carved with the egg and tongue ornament
Ornament (architecture)
In architecture and decorative art, ornament is a decoration used to embellish parts of a building or object. Large figurative elements such as monumental sculpture and their equivalents in decorative art are excluded from the term; most ornament does not include human figures, and if present they...

.

Door-related accidents

Door safety relates to prevention of door-related accident
Accident
An accident or mishap is an unforeseen and unplanned event or circumstance, often with lack of intention or necessity. It implies a generally negative outcome which may have been avoided or prevented had circumstances leading up to the accident been recognized, and acted upon, prior to its...

s. Such accidents take place in various forms, and in a number of locations; ranging from car doors to garage doors.

Contrast door safety with door security
Door security
Door security relates to prevention of door-related burglaries. Such break-ins take place in various forms, and in a number of locations; ranging from front, back and side doors to garage doors.- Common residential door types :...

.

Severity and frequency of accidents

Accidents vary in severity and frequency. According to the National Safety Council
National Safety Council
The National Safety Council is a 501 nonprofit, nongovernmental public service organization dedicated to protecting life and promoting health. Headquartered in Itasca, Illinois, NSC is a member organization, founded in 1913 and granted a congressional charter in 1953...

 in the US, 300,000 injuries are caused by doors every year.

The types of accidents vary from relatively minor cases where doors cause damage to other objects, such as walls, to serious cases resulting in human injury, particularly to fingers. A closing door can exert up to 40 ton
Ton
The ton is a unit of measure. It has a long history and has acquired a number of meanings and uses over the years. It is used principally as a unit of weight, and as a unit of volume. It can also be used as a measure of energy, for truck classification, or as a colloquial term.It is derived from...

s per square inch of pressure
Pressure
Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...

 between the hinge
Hinge
A hinge is a type of bearing that connects two solid objects, typically allowing only a limited angle of rotation between them. Two objects connected by an ideal hinge rotate relative to each other about a fixed axis of rotation. Hinges may be made of flexible material or of moving components...

s. Because of the number of accidents taking place, there has been a surge in the number of lawsuit
Lawsuit
A lawsuit or "suit in law" is a civil action brought in a court of law in which a plaintiff, a party who claims to have incurred loss as a result of a defendant's actions, demands a legal or equitable remedy. The defendant is required to respond to the plaintiff's complaint...

s. Thus organisations may be at risk when car doors or doors within buildings are unprotected.

According to the US General Services Administration
General Services Administration
The General Services Administration is an independent agency of the United States government, established in 1949 to help manage and support the basic functioning of federal agencies. The GSA supplies products and communications for U.S...

:
"...It is essential that children's fingers be protected from being crushed or otherwise injured in the hinge space of a swinging door or gate. There are simple devices available to attach to the hinge side, ensuring that this type of injury does not occur. As the door closes, the hand is pushed out of the opening, away from harm. In addition, young children are vulnerable to injury when they fall against the other (hinged) side of doors and gates, striking projected hinges. Piano hinges are not recommended to alleviate this problem as they tend to sag over time with heavy use. Instead, an inexpensive device fitting over hinges is available on the market and should be used to ensure safety..."

Opening

Whenever a door is opened outwards there is a risk that it could strike another person. In many cases this can be avoided by architectural design
Architectural Design
Architectural Design, also known as AD, is a UK-based architectural journal first launched in 1930.In its early days it was more concerned with the British scene, but gradually became more international. It also moved away from presenting mostly news towards theme-based issues...

 which favors doors which open inwards into rooms (from the perspective of a common area such as a corridor, the door opens outwards). In cases where this is infeasible, it may be possible to avoid an accident by placing windows in the door.

Inward-hinged doors can also escalate an accident by preventing people to escape the building: people inside the building may press against the doors, and thus prevent the doors to open. This was partly the case in the Grue Church fire
Grue Church fire
The Grue Church fire happened in Grue, Norway on 26 May 1822 and took the lives of between 113 and 117 churchgoers. It is the biggest fire disaster in the history of Norway.-The church:...

 in Norway in 1822.

Doorstops

Doorstop
Doorstop
A doorstop is an object or device used to hold a door open or closed, or to prevent a door from opening too widely...

s are simple devices used to prevent a door from coming into contact with another object (typically a wall). Without the door stop damage might be done to the wall. They may either absorb the force of a moving door, or hold the door in place to prevent unintended motion.

Door guards

The purpose of door guards (also known as hinge guards, anti-finger trapping devices, or finger guards) is to reduce the number of finger trapping accidents in doors, as doors pose a risk to children especially when closing.

Door guards protect fingers in door hinges by covering the gap that is created by opening doors by covering the hinges of doors with a piece of rubber or plastic that wraps from the door frame to the door. There are also door safety products which eject the fingers from the push side of the door as it is being closed.

There are various levels of door protection. Front door protection a front anti-finger trapping device but leaves the rear hinge pin side of the door unprotected. Full door protection uses front and rear anti-finger trapping devices and ensures the hinge side of a door is fully protected.
Which level of protection is appropriate should be determined by a risk assessment
Risk assessment
Risk assessment is a step in a risk management procedure. Risk assessment is the determination of quantitative or qualitative value of risk related to a concrete situation and a recognized threat...

 of the door.

There is also handle-side door protection, which prevents the door from slamming shut on the frame, which can cause injury to fingers/hands.

Safety doors

A safety door prevents finger injuries near the hinges without the use of door guards. Rather than cover the danger area, the approach is to change the shape of the door so that an accessible gap does not form in the first place. This is achieved by adding a perfectly circular ("bull-nose" shaped) extension to the door, which moves in and out of a cavity as the door opens and closes. This prevents any part of a hand being crushed near the hinges - either inside or outside.

These doors have an operating range of slightly over 90 degrees, so their use is limited to where they come into contact with a side wall when fully open (or where they can be prevented from opening too far by a doorstop
Doorstop
A doorstop is an object or device used to hold a door open or closed, or to prevent a door from opening too widely...

).

Glass doors

Glass doors pose the risk of unintentional collision if a person believes the door to be open when it is closed, or is unaware there is a door there at all. This risk may be particularly pronounced with sliding glass doors because they often have large single panes which are hard to see. To prevent injury from glass doors, sticker
Sticker
A sticker is a type of a piece of paper or plastic, adhesive, sticky on one side, and usually with a design on the other. They can be used for decoration, depending on the situation. They can come in many different shapes, sizes and colours and are put on things such as lunchboxes, in children's...

s or other types of warnings are sometimes placed on the glass surface to make it more visible. For instance, in the UK, Regulation 14 of the Workplace (Health and Safety Regulations) 1992 requires the marking of windows and glass doors to make them conspicuous.

Fire

Special purpose fire doors are often employed in buildings to reduce the overall risk of fire, particularly by preventing the spread of fire and smoke. In cases where they are improperly installed, employed, or tampered with, the risk of fire can be increased. Door closer
Door closer
A door closer is a mechanical device that closes a door, in general after someone opens it, or after it was automatically opened. Choosing a door closer can involve the consideration of a variety of criteria...

s are sometimes used to ensure fire doors remain closed.

An additional risk in a fire is that doors may prevent access to emergency service
Emergency service
Emergency services are organizations which ensure public safety and health by addressing different emergencies. Some agencies exist solely for addressing certain types of emergencies whilst others deal with ad hoc emergencies as part of their normal responsibilities...

s personnel in order to fight the fire, rescue occupants, etc. Door breaching
Door breaching
Door breaching is a process used by military, police, or emergency services to force open closed and/or locked doors. A wide range of methods are available, one or more of which may be used in any given situation...

 techniques may be required in these situations to gain access.

Panic bars are often used in buildings so that a door locked from the exterior can quickly and easily be opened from the inside in the event of a fire or other emergency.

Automobile doors

There may be an increased risk of trapping hands or fingers in car doors compared to other types of doors. In some car accidents, injury to occupants from the movement of car doors may occur.

Bicyclists often fear collision with an opening car door in case the car's occupant does not look carefully to check that it is safe to open the door. Because cyclists often ride near parked cars along the side of the road (see door zone
Door zone
The door zone is the space spanning about four feet from the sides of parallel parked cars. It is hazardous to ride a bicycle or motorcycle in a door zone because if a door is suddenly opened, the cyclist must either crash into it , brake suddenly, or swerve into the adjacent lane of traffic...

) they are particularly vulnerable to this.

Aircraft doors

Doors which lead from interior, pressurized, sections of an aircraft to exterior or unpressurized areas can pose extreme risk if they are inadvertently opened during flight. A number of accidents have occurred where aircraft doors were opened in flight:
  • American Airlines Flight 96
    American Airlines Flight 96
    American Airlines Flight 96 was a regular McDonnell Douglas DC-10-10 flight operated by American Airlines. The flight suffered a cargo door failure on 12 June 1972 while flying over Windsor, Ontario; it is thus sometimes referred to as the Windsor incident.The rapid decompression in the cargo hold...

     (also see the article on Dan Applegate
    Dan Applegate
    F. D. "Dan" Applegate was Director of Product Engineering for Convair, a McDonnell Douglas subcontractor during the early 1970s. He rose from relative obscurity to become the subject of a classic case in engineering ethics when he penned what became known as the "Applegate Memorandum".On June 12,...

     for some background and details)
  • Pan Am Flight 125
    Pan Am Flight 125
    Pan Am Flight 125 was a scheduled flight from London Heathrow Airport to New York's John F. Kennedy International Airport on March 10, 1987. It suffered a cargo door failure that pointed to a fundamental design flaw in the early model Boeing 747s, a failure mode that was repeated with fatal...

  • United Airlines Flight 811
    United Airlines Flight 811
    United Airlines Flight 811 experienced a cargo door failure in flight on Friday, February 24, 1989, after its stopover at Honolulu International Airport, Hawaii...

  • Turkish Airlines Flight 981
    Turkish Airlines Flight 981
    Turkish Airlines Flight 981 was a McDonnell Douglas DC-10, registered TC-JAV and named the Ankara, that crashed in Fontaine-Chaalis, Oise, France, outside Senlis, on 3 March 1974...


See also

  • Janus
    Janus
    -General:*Janus , the two-faced Roman god of gates, doors, doorways, beginnings, and endings*Janus , a moon of Saturn*Janus Patera, a shallow volcanic crater on Io, a moon of Jupiter...

    , Roman god of doors
  • Access badge
    Access badge
    An access badge is a credential used to gain entry to an area having automated access control entry points. Entry points may be doors, turnstiles, parking gates or other barriers....

  • Access control
    Access control
    Access control refers to exerting control over who can interact with a resource. Often but not always, this involves an authority, who does the controlling. The resource can be a given building, group of buildings, or computer-based information system...

  • Alarm
    Alarm
    An alarm device or system of alarm devices gives an audible or visual alarm signal about a problem or condition.Alarm devices include:* burglar alarms, designed to warn of burglaries; this is often a silent alarm: the police or guards are warned without indication to the burglar, which increases...

  • Alarm management
    Alarm management
    Alarm management is the application of human factors along with instrumentation engineering and systems thinking to manage the design of an alarm system to increase its usability...

  • Bank vault
    Bank vault
    A bank vault is a secure space where money, valuables, records, and documents can be stored. It is intended to protect their contents from theft, unauthorized use, fire, natural disasters, and other threats, just like a safe...

  • Biometrics
    Biometrics
    Biometrics As Jain & Ross point out, "the term biometric authentication is perhaps more appropriate than biometrics since the latter has been historically used in the field of statistics to refer to the analysis of biological data [36]" . consists of methods...

  • Burglar alarm
    Burglar alarm
    Burglar , alarms are systems designed to detect unauthorized entry into a building or area. They consist of an array of sensors, a control panel and alerting system, and interconnections...

  • Cat flap
    Cat flap
    A cat flap or cat door is a hinged flap set into a door, wall or window to allow cats to enter and exit a house on their own without needing a human to open the door, while offering a degree of protection against wind and rain entering the dwelling...


  • Closed-circuit television
    Closed-circuit television
    Closed-circuit television is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors....

  • Coal hole
    Coal hole
    A coal hole is a hatch in the pavement above an underground coal bunker. They are sometimes found outside houses that existed during the period when coal was widely used for domestic heating from the early 19th century to the middle 20th century...

  • Common Access Card
    Common Access Card
    The Common Access Card is a United States Department of Defense smart card issued as standard identification for active-duty military personnel, reserve personnel, civilian employees, other non-DoD government employees, state employees of the National Guard, and eligible contractor personnel.The...

  • Computer security
    Computer security
    Computer security is a branch of computer technology known as information security as applied to computers and networks. The objective of computer security includes protection of information and property from theft, corruption, or natural disaster, while allowing the information and property to...

  • Credential
    Credential
    A credential is an attestation of qualification, competence, or authority issued to an individual by a third party with a relevant or de facto authority or assumed competence to do so....

  • Door security
    Door security
    Door security relates to prevention of door-related burglaries. Such break-ins take place in various forms, and in a number of locations; ranging from front, back and side doors to garage doors.- Common residential door types :...

  • Double margin doors
    Double margin doors
    -Double margin doors:Peter Brett describes this door as a pair of narrow doors joined together at the meeting stile to make a single door with the appearance of a pair....

  • Electronic lock
    Electronic lock
    An electronic lock is a locking device which operates by means of electric current. Electric locks are sometimes stand-alone with an electronic control assembly mounted directly to the lock. More often electric locks are connected to an access control system...

  • Fortification
    Fortification
    Fortifications are military constructions and buildings designed for defence in warfare and military bases. Humans have constructed defensive works for many thousands of years, in a variety of increasingly complex designs...


  • ID Card
  • IP video surveillance
  • Intercom
    Intercom
    An intercom , talkback or doorphone is a stand-alone voice communications system for use within a building or small collection of buildings, functioning independently of the public telephone network. Intercoms are generally mounted permanently in buildings and vehicles...

  • Keycards
  • Locksmithing
    Locksmithing
    Locksmithing began as the science and art of making and defeating locks. A lock is a mechanism that secures buildings, rooms, cabinets, objects, or other storage facilities. A key is often used to open a lock...

  • Lock picking
    Lock picking
    Lock picking is the art of unlocking a lock by analyzing and manipulating the components of the lock device, without the original key. Although lock picking can be associated with criminal intent, it is an essential skill for a locksmith...

  • Logical security
    Logical security
    Logical Security consists of software safeguards for an organization’s systems, including user identification and password access, authentication, access rights and authority levels. These measures are to ensure that only authorized users are able to perform actions or access information in a...

  • Magnetic stripe card
    Magnetic stripe card
    A magnetic stripe card is a type of card capable of storing data by modifying the magnetism of tiny iron-based magnetic particles on a band of magnetic material on the card...

  • Optical turnstile
    Optical turnstile
    An optical turnstile is a physical security device designed to restrict or control access to a building or secure area. Optical turnstiles are usually a part of an access control system, which also consists of software, card readers, and controllers...


  • Paper honeycomb
    Paper honeycomb
    Paper honeycomb is a building and packing material. One of the most commons uses of paper honeycomb is for standard doors inside houses. Typically a layer of fiberglass and then the enforced paper made into honeycomb shapes and then another layer of fiberglass...

  • Photo identification
    Photo identification
    Photo identification is generally used to define any form of identity document that includes a photograph of the holder.Some countries use a government issued card as a proof of age or citizenship.Types of photo ID cards include:*Passports...

  • Physical Security Professional
    Physical Security Professional
    A Physical Security Professional is a certification process for individuals involved in the physical security of organizations. This certification process is offered by ASIS International...

  • Prison
    Prison
    A prison is a place in which people are physically confined and, usually, deprived of a range of personal freedoms. Imprisonment or incarceration is a legal penalty that may be imposed by the state for the commission of a crime...

  • Proximity card
    Proximity card
    Proximity card is a generic name for contactless integrated circuit devices used for security access or payment systems. The standard can refer to the older 125 kHz devices or the newer 13.56 MHz contactless RFID cards, most commonly known as contactless smartcards.Modern proximity cards...

  • Razor wire
    Razor wire
    Barbed tape or razor wire is a mesh of metal strips with sharp edges whose purpose is to prevent passage by humans. The term "razor wire", through long usage, has generally been used to describe barbed tape products...

  • Roller shutter
    Roller shutter
    A roller shutter, roller door or sectional overhead door is a type of door or window shutter consisting of many horizontal slats hinged together. The door is raised to open it and lowered to close it. On large doors, the action may be motorized. It provides protection against wind and rain...

  • Safe
    Safe
    A safe is a secure lockable box used for securing valuable objects against theft or damage. A safe is usually a hollow cuboid or cylinder, with one face removable or hinged to form a door. The body and door may be cast from metal or formed out of plastic through blow molding...

  • Safe-cracking
    Safe-cracking
    Safe-cracking is the process of opening a safe without either the combination or key. It may also refer to a computer hacker's attempts to break into a secured computer system, in which case it may be shortened to "cracking" or black hat hacking....


  • Security
    Security
    Security is the degree of protection against danger, damage, loss, and crime. Security as a form of protection are structures and processes that provide or improve security as a condition. The Institute for Security and Open Methodologies in the OSSTMM 3 defines security as "a form of protection...

  • Security engineering
    Security engineering
    Security engineering is a specialized field of engineering that focuses on the security aspects in the design of systems that need to be able to deal robustly with possible sources of disruption, ranging from natural disasters to malicious acts...

  • Security lighting
    Security lighting
    In the field of physical security, security lighting is often used as a preventative and corrective measure against intrusions or other criminal activity on a physical piece of property. Security lighting may be provided to aid in the detection of intruders, to deter intruders, or in some cases...

  • Security policy
    Security policy
    Security policy is a definition of what it means to be secure for a system, organization or other entity. For an organization, it addresses the constraints on behavior of its members as well as constraints imposed on adversaries by mechanisms such as doors, locks, keys and walls...

  • Smart card
    Smart card
    A smart card, chip card, or integrated circuit card , is any pocket-sized card with embedded integrated circuits. A smart card or microprocessor cards contain volatile memory and microprocessor components. The card is made of plastic, generally polyvinyl chloride, but sometimes acrylonitrile...

  • Surveillance
    Surveillance
    Surveillance is the monitoring of the behavior, activities, or other changing information, usually of people. It is sometimes done in a surreptitious manner...

  • Swipe card
  • Wiegand effect
    Wiegand effect
    The Wiegand effect is a nonlinear magnetic effect, named after its discoverer John R. Wiegand, produced in specially annealed and hardened wire called Wiegand wire....

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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