A door is a panel that makes an opening in a building, room or vehicle. Doors are usually made of a hard, semi-permeable, and hard-to-break substance (such as wood or metal), but sometimes consisting of a hard frame into which windows or screens have been fitted. Doors are often attached by hinges to a frame. Doors make ingress into or egress from a building, room, or vehicle easier to manage. The panel may be moved in various ways (at angles away from the frame, by sliding on a plane parallel to the frame, by folding in angles on a parallel plane, or by spinning along an axis at the center of the frame) to allow or prevent ingress or egress. In most cases, a door's interior matches its exterior side. But in other cases (e.g., a vehicle door) the two sides are radically different.
Often doors have locking mechanisms to ensure that only some people can open them. Doors can have devices such as knockers or doorbells by which people outside can announce their presence and summon someone either to open the door for them or give permission to open and enter. Apart from providing access into and out of a space, doors can have the secondary functions of ensuring privacy by preventing unwanted attention from outsiders, of separating areas with different functions, of allowing light to pass into and out of a space, of controlling ventilation or air drafts so that interiors may be more effectively heated or cooled, of dampening noise, and of blocking the spread of fire.
Doors may have aesthetic, symbolic, ritualistic purposes. To be given the key to a door can signify a change in status from outsider to insider. Doors and doorways frequently appear in literature and the arts with metaphorical or allegorical import as a portent of change.
The earliest in records are those represented in the paintings of some Egyptian tombs, in which they are shown as single or double doors, each in a single piece of wood. Doors were once believed to be the literal doorway to the afterlife, and some doors leading to important places included designs of the afterlife. 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 (iv. 6.) was done with stiles (sea/si) and rails (see: Frame and panel): 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 or hinged, 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 made of timber, such as those referred to in the Biblical depiction of King Solomon's temple being in olive wood (I Kings vi. 31-35), which were carved and overlaid with gold. The doors dwelt upon in Homer 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.
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, the latter being always in some hard stone such as basalt or granite. Those found at Nippur by Dr. Hilprecht dating from 2000 B.C. were in dolerite. The tenons of the gates at Balawat were sheathed with bronze (now in the British Museum). These doors or gates were hung in two leaves, each about 8 ft 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 (360 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 in Syria, where timber is scarce the doors were made in stone, and one measuring 5 ft 4 in (1.63 m) by 2 ft 7 in (0.79 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 (3.0 m). high, being the entrance doors of the town. In Etruria many stone doors are referred to by Dennis.
The ancient Greek and Roman doors were either single doors, double doors, triple doors, sliding doors or folding doors, in the last case the leaves were hinged and folded back. In Eumachia, 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, 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 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.
The Greek scholar Heron of Alexandria created the earliest known automatic door in the 1st century AD during the era of Roman Egypt. The first foot-sensor-activated automatic door was made in China during the reign of Emperor Yang of Sui (r. 604–618), who had one installed for his royal library. The first automatic gate operators were later created in 1206 by Arab inventor Al-Jazari.
Copper and its alloys were integral in medieval architecture. The doors of the church of the Nativity at Bethlehem (6th century) are covered with plates of bronze, cut out in patterns. Those of Hagia Sophia at Constantinople, of the 8th and 9th century, are wrought in bronze, and the west doors of the cathedral of Aix-la-Chapelle (9th century), of similar manufacture, were probably brought from Constantinople, as also some of those in St. Marks, Venice. The bronze doors on the Aachen Cathedral in Germany date back to about AD 800. Bronze baptistery doors at the Cathedral of Florence were completed in 1423 by Ghiberti. (For more information, see: Copper in architecture).
Of the 11th and 12th centuries there are numerous examples of bronze doors, the earliest being one at Hildesheim, Germany (1015). The Hildesheim design affected the concept of Gniezno door in Poland. Of others in South Italy and Sicily, the following are the finest: in Sant Andrea, Amalfi (1060); Salerno (1099); Canosa (1111); Troia, two doors (1119 and 1124); Ravello (1179), by Barisano of Trani, who also made doors for Trani cathedral; and in Monreale 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; in France the metal work of the doors of Notre Dame 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), 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 (1330), and of the east doorway by Ghiberti (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 speaks.
The doors of the mosques in Cairo 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 Coptic in its origin. The doors of the palace at Palermo, which were made by Saracenic workmen for the Normans, are fine examples and in good preservation. A somewhat similar decorative class of door to these latter is found in 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 and Louis XV 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, which is in two leaves, is entirely carried out as if consisting of one great panel only.
The earliest Renaissance doors in France are those of the cathedral of St. Sauveur at Aix (1503). In the lower panels there are figures 3 ft (0.91 m). high in Gothic niches, and in the upper panels a double range of niches with figures about 2 ft (0.61 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 (1575) are carved with figures in niches subdivided by classic pilasters superimposed. In St. Maclou at Rouen 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.
NASA's Vehicle Assembly Building at the Kennedy Space Center contains the four largest doors. The Vehicle Assembly Building was originally built for the assembly of the Apollo missions' Saturn vehicles and was then used to support Space Shuttle operations. Each of the four doors are 139 meters (456 feet) high.
The oldest door in England can be found in Westminster Abbey and dates from 1050. In England in the 17th century the door panels were raised with bolection or projecting moldings, sometimes richly carved, round them; in the 18th century the moldings worked on the stiles and rails were carved with the egg and tongue ornament.
There are many kinds of doors, with different purposes. The most common type is the single-leaf door, which consists of a single rigid panel that fills the doorway. There are many variations on this basic design, such as the double-leaf door or double door and French windows, which have two adjacent independent panels hinged on each side of the doorway.
Most doors are hinged along one side to allow the door to pivot away from the doorway in one direction, but not the other. The axis of rotation is usually vertical. In some cases, such as hinged garage doors, 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 or airplanes, such as for the door to the toilet, which opens inward.
A swing door has special double-action hinges that allow it to open either outwards or inwards, and is usually sprung to keep it closed.
A selfbolting door has special hinges that permit the panel leaf to move laterally, so that the door itself becomes a giant bolt for better security. 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 a door with lites where all or some panels would be in a casement door. A French door traditionally has a moulded panel at the bottom of the door. It is called a French window when used in a pair as double-leaved doors with large glass panels in each door leaf, and in which the doors may swing out (typically) as well as in.
A Mead door, developed by S Mead of Leicester, swings both ways. It is susceptible to forced entry due to its design.
A Dutch door or stable door consists of two halves. The top half operates independently from the bottom half. A variant exists in which opening the top part separately is possible, but because the lower part has a lip on the inside, closing the top part, while leaving the lower part open, is not.
A garden door resembles a French window (with lites), but is more secure because only one door is operable. The hinge of the operating door is next to the adjacent fixed door and the latch is located at the wall opening jamb rather than between the two doors or with the use of an espagnolette bolt.
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 inside a wall cavity are called pocket doors. This type of door is used in tight spaces where privacy is also required. The door slab is mounted to roller and a track at the top of the door and slides inside a wall.
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, although they are not counted as fire exit doors. The door that moves is called the "active leaf", while the door that remains fixed is called the "inactive leaf".
A revolving door has several wings or leaves, generally four, radiating from a central shaft, forming compartments that rotate about a vertical axis. A revolving door allows people to pass in both directions without colliding, and forms an airlock maintaining a seal between inside and out.
A pivot door, instead of hinges, is supported on a bearing some distance away from the edge, so that there is more or less of a gap on the pivot side as well as the opening side. In some cases the pivot is central, creating two equal openings.
A high-speed door is a very fast door some with opening speeds of up to 4 m/s, mainly used in the industrial sector where the speed of a door has an effect on production logistics, temperature and pressure control. high-speed clean room doors are used in pharmaceutical industries for the special curtain and stainless steel frames. They guarantee the tightness of all accesses. The powerful high-speed doors have a smooth surface structure and no protruding edges. Therefore, they can be easily cleaned and depositing of particles is largely excluded.
High-speed doors are made to handle a high number of openings, generally more than 200,000 a year. They need to be built with heavy-duty parts and counterbalance systems for speed enhancement and emergency opening function. The door curtain was originally made of PVC, but was later also developed in aluminium and acrylic glass sections. High Speed refrigeration and cold room doors with excellent insulation values was also introduced with the Green and Energy saving requirements.
In North America, the Door and Access Systems Manufacturing Association (DASMA) defines high-performance doors as non-residential, powered doors, characterized by rolling, folding, sliding or swinging action, that are either high-cycle (minimum 100 cycles/day) or high-speed (minimum 20 inches(508 mm)/second), and two out of three of the following: made-to-order for exact size and custom features, designed to be able to withstand equipment impact (break-away if accidentally hit by vehicle) or designed to sustain heavy usage with minimal maintenance.
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:
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.A mechanism is set in modern automatic doors to ensure that door will be in open state in case of power failure.
Up-and-over or overhead doors are often used in garages. Instead of hinges it has a mechanism, often counterbalanced or sprung, that allows it to be lifted so that it rests horizontally above the opening. A roller shutter or sectional overhead door is one variant of this type.
A tambour door or roller 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.
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 or overlap (i.e. a Rabbet) on the vertical edge(s) where they meet. Fire-rating can be achieved with an applied edge-guard or astragal molding on the meeting stile, in accordance with the American Fire door.
Evolution Door is a trackless door that moves in the same closure level as a sliding door. The system is an invention of the Austrian artist Klemens Torggler. It is a further development of the Drehplattentür that normally consists of two rotatable, connected panels which move to each other when opening.
Architectural doors have numerous general and specialized uses. Doors are generally used to separate interior spaces (closets, rooms, etc.) for convenience, privacy, safety, and security reasons. Doors are also used to secure passages into a building from the exterior, for reasons of climate control and safety.
Doors also are applied in more specialized cases:
Panel doors, also called stile and rail doors, are built with frame and panel construction. EN 12519 is describing the terms which are officially used in European Member States. The main parts are listed below:
Also known as ledges and braced, Board and batten doors are an older design consisting primarily of vertical slats:
As board and Batten 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. Impact-resistant doors excel in high traffic areas such as hospitals, schools, hotels and coastal areas.
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.
Many modern doors, including most interior doors, are flush doors:
Door swings For most of the world, door swings, or handing, are determined while standing on the outside or less secure side of the door while facing the door (i.e., standing on the side requiring a key to open, going from outside to inside, or from public to private).
It is especially important to get the hand and swing correct 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 or swing will cause the door to bind, not close properly or leak (for exterior doors). Fixing this specification error will be expensive or time consuming. In North America, many doors now come with factory-installed hinges, pre-hung on the jamb and sills.
While facing the door from the outside or less secure side, 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,
One of the oldest DIN standard applies: DIN 107 "Building construction; identification of right and left side" (first 1922-05, current 1974-04) defines that doors are categorized from the side where the door hinges can be seen. If the hinges are on the left, it is a DIN Left door (DIN links, DIN gauche), if the hinges are on the right, it is a DIN Right door (DIN rechts, DIN droite). The DIN Right and DIN Left marking are also used to categorize matching installation material such as mortise locks (referenced in DIN 107). The European Standard DIN EN 12519 "Windows and pedestrian doors. Terminology" includes these definitions of orientation.
The "refrigerator rule" applies, and a refrigerator door is not opened from the inside. If the hinges are on the right then it is a right hand (or right hung) door. (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.
Wooden doors – including solid wood doors – are a top choice for many homeowners, largely because of the aesthetic qualities of wood. Many wood doors are custom-made, but they have several downsides: their price, their maintenance requirements (regular painting and staining) and their limited insulating value  (R-5 to R-6, not including the effects of the glass elements of the doors). Wood doors often have an overhang requirement to maintain a warranty. An overhang is a roof, porch area or awning that helps to protect the door and its finish from UV rays.
Steel doors are another major type of residential front doors; most of them come with a polyurethane or other type of foam insulation core – a critical factor in a building's overall comfort and efficiency.
Most modern exterior walls are designed to provide thermal insulation and energy efficiency, which can be indicated by the Energy Star label or the Passive House standards. Premium composite (including steel doors with a thick core of polyurethane or other foam), fiberglass and vinyl doors benefit from the materials they are made from, from a thermal perspective.
But there are very few door models with an R-value close to 10 (which is far less than the R-40 walls or the R-50 ceilings of super-insulated buildings – Passive Solar and Zero Energy Buildings). Typical doors are not thick enough to provide very high levels of energy efficiency.
Many doors may have good R-values at their center, but their overall energy efficiency is reduced because of the presence of glass and reinforcing elements, or because of poor weatherstripping and the way the door is manufactured.
Door weatherstripping is particularly important for energy efficiency. German-made Passive House doors use multiple weatherstrips, including magnetic strips, to meet higher standards. These weatherstrips are critical to reduce to a minimum energy losses due to air leakage.
The standard door sizes in the US run along 2" increments. Customary sizes have a height of 78" (1981 mm) or 80" (2032 mm) and a width of 18" (472 mm), 24" (610 mm), 26" (660 mm), 28" (711 mm), 30" (762 mm) or 36" (914 mm). Most residential passage (room to room) doors are 30" x 80" (762 mm x 2032 mm).
A standard US residential (exterior) door size is 36" x 80" (91 x 203 cm). Interior doors for wheelchair access must also have a minimum width of 3'-0" (91 cm). Residential interior doors are often somewhat smaller being 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.
Thickness: Most pre-fabricated doors are 1 3/8" thick (for interior doors) or 1 3/4" (exterior).
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. Two car garage doors (sometimes called double car doors) are a single door 16'-0". Because of size and weight these doors are usually sectional. That is split into four or five horizontal sections so that they can be raised more easily and don't require a lot of additional space above the door when opening and closing. There are single piece double garage doors found in some older homes. circa 1950's
The standard DIN doors are defined in DIN 18101 (published 1955-07, 1985-01, 2014-08). The door sizes are also given in the construction standard for wooden door panels (DIN 68706-1). The DIN commission was also responsible for the harmonized European standard DIN EN 14351-1 for exterior doors and DIN EN 14351-2 for interior doors (published 2006-07, 2010-08), which defines the requirements for the CE marking giving standard sizes by examples in the appendix.
The DIN 18101 standard has a normative size (Nennmaß) slightly larger than the panel size (Türblatt) as the standard derives the panel sizes from the normative size being different single door vs double door and molded vs unmolded doors. The DIN 18101/1985 defines interior single molded doors to have a common panel height of 1985 mm (normativ height 2010 mm) at panel widths of 610 mm, 735 mm, 860 mm, 985 mm, 1110 mm, plus a larger door panel size of 1110 mm x 2110 mm. The newer DIN 18101/2014 drops the definition of just five standard door sizes in favor of a basic raster running along 125 mm increments where the height and width are independent. The panel width may be in the range 485 mm to 1360 mmm, and the height may be in the range of 1610 mm to 2735 mm. The most common interior door is 860 mm x 1985 mm (33.8" x 78.1").
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 for a discussion of attachments to doors such as door handles, doorknobs, and door knockers.
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.
Door safety relates to prevention of door-related accidents. Such accidents take place in various forms, and in a number of locations; ranging from car doors to garage doors. Accidents vary in severity and frequency. According to the National Safety Council in the United States, 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, hands, and feet. A closing door can exert up to 40 tons per square inch of pressure between the hinges. Because of the number of accidents taking place, there has been a surge in the number of lawsuits. Thus organisations may be at risk when car doors or doors within buildings are unprotected.
According to the US General Services Administration:
...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...
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 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.
However, inward-hinged doors can also escalate an accident by preventing people from escaping the building: people inside the building may press against the doors, and thus prevent the doors from opening. This was partly the case in the Grue Church fire in Norway in 1822.
Today, the exterior doors of most large (especially public) buildings open outward, while interior doors such as doors to individual rooms, offices, suites, etc. open inward, as do many exterior doors of houses, particularly in North America.
Doorstops 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.
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 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.
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).
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 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, stickers 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. Australian Standards: AS1288 and AS2208 require glass doors to be made from laminated, tempered or toughened glass.
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 closers are sometimes used to ensure fire doors remain closed.
An additional risk in a fire is that doors may prevent access to emergency services personnel in order to fight the fire, rescue occupants, etc. Door breaching 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.
There may be an increased risk of trapping hands or fingers in car doors compared to other types of doors, due to the proximity in which the occupant sits. 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) they are particularly vulnerable.
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. This can be mitigated by having doors that open inwardly and are designed to be forced into their door frames by the internal cabin pressure – most cabin doors are of this type. However, an outward opening door is often advantageous for cargo doors to maximise available space, and these need to be secured by hefty locking mechanisms to overcome internal pressure.
A number of accidents have occurred where outward-opening aircraft doors were opened in flight, often accidentally:
The BMW 3 Series is a compact executive car manufactured by the German automaker BMW since May 1975. It is the successor to the 02 Series and has been produced in seven different generations.
The first generation of the 3 Series was only available as a 2-door sedan, however the model range has since expanded to include a 4-door sedan, 2-door convertible, 2-door coupé, 5-door station wagon, 5-door hatchback ("Gran Turismo") and 3-door hatchback body styles. Since 2013, the coupé and convertible models have been marketed as the 4 Series, therefore the 3 Series range no longer includes these body styles.
The 3 Series is BMW's best-selling model, accounting for around 30% of the BMW brand's annual total sales (excluding motorbikes). The BMW 3 Series has won numerous awards throughout its history.
The M version of the 3 series, M3, debuted with the E30 M3 in 1986.Chancel
In church architecture, the chancel is the space around the altar, including the choir and the sanctuary (sometimes called the presbytery), at the liturgical east end of a traditional Christian church building. It may terminate in an apse. It is generally the area used by the clergy and choir during worship, while the congregation is in the nave. Direct access may be provided by a priest's door, usually on the south side of the church. This is one definition, sometimes called the "strict" one; in practice in churches where the eastern end contains other elements such as an ambulatory and side chapels, these are also often counted as part of the chancel, especially when discussing architecture. In smaller churches, where the altar is backed by the outside east wall and there is no distinct choir, the chancel and sanctuary may be the same area. In churches with a retroquire area behind the altar, this may only be included in the broader definition of chancel.
In a cathedral or other large church, there may be a distinct choir area at the start of the chancel (looking from the nave), before reaching the sanctuary, and an ambulatory may run beside and behind it. All these may be included in the chancel, at least in architectural terms (see above). In many churches, the altar has now been moved to the front of the chancel, in what was built as the choir area, or to the centre of the transept, somewhat confusing the distinction between chancel, choir and sanctuary. In churches with less traditional plans, the term may not be useful in either architectural or ecclesiastical terms. The chancel may be a step or two higher than the level of the nave, and the sanctuary is often raised still further. The chancel is very often separated from the nave by altar rails, or a rood screen, a sanctuary bar, or an open space, and its width and roof height is often different from that of the nave; usually the chancel will be narrower and lower.
In churches with a traditional Latin cross plan, and a transept and central crossing, the chancel usually begins at the eastern side of the central crossing, often under an extra-large chancel arch supporting the crossing and the roof. This is an arch which separates the chancel from the nave and transept of a church. If the chancel, strictly defined as choir and sanctuary, does not fill the full width of a medieval church, there will usually be some form of low wall or screen at its sides, demarcating it from the ambulatory or parallel side chapels.
As well as the altar, the sanctuary may house a credence table and seats for officiating and assisting ministers. In some churches, the congregation may gather on three sides or in a semicircle around the chancel. In some churches, the pulpit and lectern may be in the chancel, but in others these, especially the pulpit, are in the nave.Coupé
A coupé or coupe is a two-door car with a fixed roof. In the 21st century there are four-door cars with a coupé-like roofline sold as "four door coupés" or "quad coupés".
Coupé was first applied to horse-drawn carriages for two passengers without rear-facing seats.Elevator
An elevator (US and Canada) or lift (Commonwealth countries) is a type of vertical transportation that moves people or goods between floors (levels, decks) of a building, vessel, or other structure. Elevators are typically powered by electric motors that drive traction cables and counterweight systems like a hoist, although some pump hydraulic fluid to raise a cylindrical piston like a jack.
In agriculture and manufacturing, an elevator is any type of conveyor device used to lift materials in a continuous stream into bins or silos. Several types exist, such as the chain and bucket elevator, grain auger screw conveyor using the principle of Archimedes' screw, or the chain and paddles or forks of hay elevators. Languages other than English may have loanwords based on either elevator or lift. Because of wheelchair access laws, elevators are often a legal requirement in new multistory buildings, especially where wheelchair ramps would be impractical.
There are also some elevators which can go sideward in addition to the usual up-and-down motion.Ford Escort (Europe)
The Ford Escort is a small family car which was manufactured by Ford Europe from 1968 to 2004. The Ford Escort name was also applied to several different small cars produced in North America by Ford between 1981 and 2003.
In 2014, Ford revived the Escort name for a car based on the second-generation Ford Focus sold on the Chinese market.Ford Explorer
The Ford Explorer is a range of SUVs manufactured by Ford Motor Company. Introduced in 1990 for the 1991 model year, the Explorer was the first four-door SUV produced by Ford, replacing the two-door Bronco II. Five generations of the Explorer have been produced; a sixth generation (to commence production for 2020) was unveiled in January 2019. As with the Ranger, the Explorer derives its name from a trim package used on the F-Series, used from 1968 to 1986. Originally slotted below the full-size Bronco in the Ford truck line, the current Explorer is slotted between the Escape/Kuga, Edge and standard-wheelbase Expedition.
For its first two generations, the Explorer was produced in both two-door (as the Explorer Sport) and four-door configurations. Upon the introduction of the third generation, the Explorer was produced exclusively as a four-door SUV; the Explorer Sport was discontinued in 2003. The Sport name was resurrected in 2013, but as a performance version of the standard four-door Explorer. The Explorer has been offered with a number of powertrain layouts during its production. The first four generations offered rear-wheel drive as standard, with part-time four-wheel drive and all-wheel drive options; the fifth generation offered front-wheel drive and all-wheel drive, while the sixth generation reverted back to rear-wheel drive with optional all-wheel drive.
During its production, numerous variants of the Explorer have been marketed, with Lincoln-Mercury selling the four-door Explorer as the Mercury Mountaineer (1997-2010) and the Lincoln Aviator (2003-2005; 2020-); Mazda sold the Explorer Sport as the Mazda Navajo (1991-1994). The Explorer Sport Trac is a mid-size pickup truck derived from the four-door Explorer; two generations were produced from 2001 to 2010. For police use, Ford developed the Ford Police Interceptor Utility from the fifth-generation Explorer (replacing the Ford Crown Victoria Police Interceptor); a specially modified Special Service Vehicle version is also available from Ford Fleet for law enforcement agencies, fire departments, and EMS agencies.Ford Fiesta
The Ford Fiesta is a supermini marketed by Ford since 1976 over seven generations, including in Europe, Australia, Brazil, Argentina, Mexico, China, India, Thailand, and South Africa. It has been manufactured in many countries.
In 2008, the seventh generation Fiesta (Mark VII) was introduced worldwide, making it the first Fiesta model to be sold in North America since the Fiesta Mark I was discontinued at the end of 1980.
Ford has sold over 16 million Fiestas since 1976, making it one of the best selling Ford marques behind the Escort and the F-Series.Freight transport
Freight transport is the physical process of transporting commodities and merchandise goods and cargo. The term shipping originally referred to transport by sea but in American English, it has been extended to refer to transport by land or air (International English: "carriage") as well. "Logistics", a term borrowed from the military environment, is also used in the same sense.Hatchback
A hatchback is a car with a hatch-type rear door that opens upwards and often a shared volume for the passenger and cargo areas.
When the body style of a car is described as a hatchback, typically it is referring to a utilitarian small car; however hatchback doors are also used on several sports cars, SUVs and large luxury cars. The modern form of the hatchback body style was developed through the 1960s and rose in popularity through the 1970s.Honda Civic
The Honda Civic (Japanese: ホンダ・シビック, Honda Shibikku) is a line of cars manufactured by Honda. Originally a subcompact, the Civic has gone through several generational changes, becoming both larger and more upscale, moving into the compact car segment. EPA guidelines for vehicle size class stipulate a car having combined passenger and cargo room of 110 to 119.9 cubic feet (3,110 to 3,400 L) is considered a mid-size car, and as such the tenth generation Civic sedan is technically a small-end mid-size car, although it still competes in the compact class. The Civic coupe is still considered a compact car. The Civic currently falls between the Honda Fit and Accord.
The first Civic was introduced in July 1972 as a two-door model, followed by a three-door hatchback that September. With an 1169 cc transverse engine and front-wheel drive like the British Mini, the car provided good interior space despite overall small dimensions. Initially gaining a reputation for being fuel-efficient, reliable, and environmentally friendly, later iterations have become known for performance and sportiness, especially the Civic Type R, Civic VTi, Civic GTi and Civic SiR/Si.The Civic has been repeatedly rebadged for international markets, and served as the basis for the Honda CR-X, the Honda CR-X del Sol, the Concerto, the first generation Prelude, the Civic Shuttle (later to become the Orthia), and the CR-V.
In Japan, as customers increasingly shifted to minivans and compact cars like the Fit, production of the non-hybrid Civic ended in August 2010 when it no longer complied with Japanese government dimension regulations in the width category. However, the Civic was reintroduced into the Japanese market with the launch of the tenth-generation model in 2017.Jeep Wrangler
The Jeep Wrangler is a series of compact and mid-size (Wrangler Unlimited and Wrangler 2-door JL) four-wheel drive off-road SUVs, manufactured by Jeep since 1986, and currently in its fourth generation. The Wrangler JL, the most recent generation, was unveiled in late 2017 and is produced at Jeep's Toledo Complex.
The Wrangler is arguably an indirect progression from the World War II Jeep, through the CJ (Civilian Jeeps) produced by Willys, Kaiser-Jeep and American Motors Corporation (AMC) from the mid-1940s through 1980s. Although neither AMC nor Chrysler (after its purchase of AMC in 1987) have claimed that the Wrangler was a direct descendant of the original military model — both the CJ Jeeps and the conceptually consistent Wrangler, with their solid axles and open top, have been called the Jeep model as central to Jeep's brand identity as the rear-engined 911 is to Porsche.Similar to the Willys MB and the CJ Jeeps before it, all Wrangler models continue to use a separate body and frame, rigid live axles both front and rear, a tapering nose design with flared fenders, a fold-flat windshield, and can be driven without doors. Also, with few exceptions, they have part-time four-wheel drive systems, with the choice of high and low gearing, and standard are open bodies with removable hard- or soft-tops. However, the Wrangler series was specifically redesigned to be safer and more comfortable on-road, to attract more daily drivers, by upgrading its suspension, drivetrain, and interior, compared to the CJ line. The suspension on all Wranglers included trackbars and anti-roll bars, and, from the 1997 TJ onwards, front and rear coil springs instead of the previous leaf-springs.From 2004 the Wrangler has been complemented with long-wheelbase versions, called Wrangler Unlimited (until the release of the JL generation). 2004-2006 models were longer versions with 2 doors. In 2004 only automatic transmission equipped “Unlimited” versions were sold. In 2005 both an automatic and manual 6-speed (NSG-370) were offered. Since 2007, the long-wheelbase Wranglers were four-door models, offering over 20 in (508 mm) more room. By mid 2017 the four-door models represented three quarters of all new Wranglers on the market.Knockin' on Heaven's Door
"Knockin' on Heaven's Door" is a song by Bob Dylan, written for the soundtrack of the 1973 film Pat Garrett and Billy the Kid. Released as a single two months after the film's release, it became a worldwide hit, reaching the Top 10 in several countries. The song has became one of Dylan's most popular and most covered post-1960s compositions, spawning covers from Guns N' Roses, Eric Clapton, Randy Crawford, and many more. Described by Dylan biographer, Clinton Heylin, as "an exercise in splendid simplicity", the song features two verses, each of which represent the films title characters and American frontier legends Pat Garrett and Billy the Kid.Mitsubishi Pajero
The Mitsubishi Pajero (; Spanish: [paˈxeɾo]; Japanese パジェロ [pad͡ʑeɾo]) is a mid-sized sport utility vehicle manufactured and marketed globally by Mitsubishi.
Mitsubishi markets the SUV as the Montero in Spain, the Philippines and the Americas, except Brazil and Jamaica — and as the Shogun in the United Kingdom. However, Montero is no longer sold in North America since late 2006. The Pajero nameplate derives from Leopardus pajeros, the Pampas cat.Modified versions of the Pajero are noted for having won the Dakar Rally 12 times.Due to their success, the Pajero, Montero and Shogun names were also applied to other, mechanically unrelated models, such as the Pajero Mini kei car, the Pajero Junior and Pajero iO/Pinin mini SUVs, and the Mitsubishi Pajero/Montero/Shogun Sport.Monty Hall problem
The Monty Hall problem is a brain teaser, in the form of a probability puzzle, loosely based on the American television game show Let's Make a Deal and named after its original host, Monty Hall. The problem was originally posed (and solved) in a letter by Steve Selvin to the American Statistician in 1975 (Selvin 1975a), (Selvin 1975b). It became famous as a question from a reader's letter quoted in Marilyn vos Savant's "Ask Marilyn" column in Parade magazine in 1990 (vos Savant 1990a):
Suppose you're on a game show, and you're given the choice of three doors: Behind one door is a car; behind the others, goats. You pick a door, say No. 1, and the host, who knows what's behind the doors, opens another door, say No. 3, which has a goat. He then says to you, "Do you want to pick door No. 2?" Is it to your advantage to switch your choice?
Vos Savant's response was that the contestant should switch to the other door (vos Savant 1990a). Under the standard assumptions, contestants who switch have a 2/3 chance of winning the car, while contestants who stick to their initial choice have only a 1/3 chance.
The given probabilities depend on specific assumptions about how the host and contestant choose their doors. A key insight is that, under these standard conditions, there is more information about doors 2 and 3 that was not available at the beginning of the game, when door 1 was chosen by the player: the host's deliberate action adds value to the door he did not choose to eliminate, but not to the one chosen by the contestant originally. Another insight is that switching doors is a different action than choosing between the two remaining doors at random, as the first action uses the previous information and the latter does not. Other possible behaviors than the one described can reveal different additional information, or none at all, and yield different probabilities.
Many readers of vos Savant's column refused to believe switching is beneficial despite her explanation. After the problem appeared in Parade, approximately 10,000 readers, including nearly 1,000 with PhDs, wrote to the magazine, most of them claiming vos Savant was wrong (Tierney 1991). Even when given explanations, simulations, and formal mathematical proofs, many people still do not accept that switching is the best strategy (vos Savant 1991a). Paul Erdős, one of the most prolific mathematicians in history, remained unconvinced until he was shown a computer simulation demonstrating the predicted result (Vazsonyi 1999).
The problem is a paradox of the veridical type, because the correct choice (that one should switch doors) is so counterintuitive it can seem absurd, but is nevertheless demonstrably true. The Monty Hall problem is mathematically closely related to the earlier Three Prisoners problem and to the much older Bertrand's box paradox.Pontiac Firebird
The Pontiac Firebird is an American automobile built by Pontiac from the 1967 to the 2002 model years. Designed as a pony car to compete with the Ford Mustang, it was introduced February 23, 1967, the same model year as GM's Chevrolet division platform-sharing Camaro. This also coincided with the release of the 1967 Mercury Cougar. Ford's upscale, platform-sharing version of the Mustang,The name "Firebird" was also previously used by GM for the General Motors Firebird 1950s and early 1960s concept cars.Sedan (automobile)
A sedan — also saloon — is a passenger car in a three-box configuration with separate compartments for engine, passenger, and cargo.Sedan's first recorded use as a name for an automobile body was in 1912. The name comes from a 17th century development of a litter, the sedan chair, a one-person enclosed box with windows and carried by porters.
Variations of the sedan style of body include: close-coupled sedan, club sedan, convertible sedan, fastback sedan, hardtop sedan, notchback sedan and sedanet/sedanette.Station wagon
A station wagon (also called an estate car, estate or wagon) is a car body style which has a "two-box design": one for the engine, and the other a passenger area that includes a large cargo area and rear tailgate hinged to open from the back for access to the cargo area. The body style is similar to hatchback cars, however, station wagons are longer, and are more likely to have the roofline extended to the rear of the car (resulting in a vertical rear surface to the car) to maximize the cargo space.
The first station wagons were produced in the US around 1910: wood-bodied conversions of existing passenger cars. During the 1930s, car manufacturers in the US, UK, and France began to produce station wagon models, and, by the 1950s, the wood rear bodywork was replaced by an all-steel body. Station wagon models sold well from the 1950s to the 1970s, however, since then, their sales have declined as minivans and SUVs have increased in popularity.Subaru Impreza
The Subaru Impreza (スバル・インプレッサ, Subaru Inpuressa) is a compact car that has been manufactured since 1992 by Subaru, introduced as a replacement for the Leone, with the predecessor's EA series engines replaced by the new EJ series.
Now in its fifth generation, Subaru has offered four-door sedan and five-door body variants since 1992; the firm also offered a coupe from 1995 until 2001, and a 5-door wagon from the Impreza's introduction in the form of a hatchback. Mainstream versions have received "boxer" flat-four engines ranging from 1.5- to 2.5-liters, with the performance-oriented Impreza WRX and WRX STI models uprated with the addition of turbochargers. Since the third generation series, some markets have adopted the abbreviated Subaru WRX name for these high-performance variants. The first three generations of Impreza in North America were also available with an off-road appearance package called the Outback Sport. For the fourth generation, this appearance package was renamed the XV (Crosstrek in North America), and, unlike the Outback Sport (which was exclusive to the North American market), is sold internationally.
The Impreza (also Impreza WRX and Impreza WRX STI) is a major rival to the Mitsubishi Lancer (and Mitsubishi Lancer Evolution).
Subaru has offered both front- and all-wheel drive layouts for the Impreza. Since the late-1990s, some markets have restricted sales to the all-wheel drive model—therefore granting the Impreza a unique selling proposition in the global compact class characterized by front-wheel drive. However, Japanese models remain available in either configuration.
A 2019 iSeeCars study named the Impreza as the lowest-depreciating sedan after five years.
|Shared residential rooms|
|Utility and storage|
|Great house areas|