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. 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. Paris is perhaps the most beautiful in execution, but examples are endless throughout France and England. French window albeit not being typical.
Jean Goujon have figures in niches on each side, and others in a group of great beauty in the center. Kennedy Space Center contains the four largest doors. There are many kinds of doors, with different purposes. This style of door has been adapted for homes. It is designed to blend with the adjacent wall in all finishes, and visually to be a part of the wall, a disguised door. The frame typically requires a weather strip at floor level and where the doors meet to prevent water ingress. The slender window joinery maximizes light into the room and minimizes the visual impact of the doorway joinery when considered externally.
The doors of a French window often open outward onto a balcony, porch, or terrace and they may provide an entrance to a garden. Florida in 1929 by Gwendolyn and Powel Crosley, that provided the desired circulation of air with an added degree of privacy in that it is impossible to see through the fins in any direction. These may also be fitted with wooden outer panels to resemble standard internal and external doors. Skins can also be made out of hardboards, the first of which was invented by William H Mason in 1924. 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. The only difference is that the surface material is a moulded skin made of MDF. Examples might be found on the ceremonial door of a cathedral or in a large vehicle door in a garage or hangar.
Wood is the most common material, and doors may also be metal or glass. Bi-fold doors are essentially now doors that let the outside in. 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. The axis of rotation is usually vertical. 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.
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. S Mead of Leicester, swings both ways. It is susceptible to forced entry due to its design. 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. It is often useful to have doors which slide along tracks, often for space or aesthetic considerations. 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. 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 allows people to pass in both directions without colliding, and forms an airlock maintaining a seal between inside and out. In some cases the pivot is central, creating two equal openings. 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 200000 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.