Doors are often taken for granted as a part of a structure, though they are important access devices.
Exterior doors provide access into the structure and control privacy safety and weather. Exterior doors may also facilitate ventilation, light or permit a view.
Interior doors control the access within a structure that is passage from one area to another. They may act as screens for storage or utility areas. They may also act as temporary partitions allowing for flexibility within a space.
Doors may be constructed of a variety of materials: Wood it may be solid, stile and rail, veneered with solid or hollow core; Steel it may be solid or hollow core; Fiberglass, and Aluminum.
Each of the above materials may have a flush face (smooth), a paneled face whether part of the door construction or embossed. Any of these doors may have glass, labeled lites in a door or louvers
Doors may operate by swinging to open, sliding, folding with commercial doors operating vertically as well as in the horizontal plane. Doors may have a fire rating or be insulated for temperature or acoustical rating.
Glass doors are a special case and usually have another material for framing, operating by swing or sliding.
Hardware: Cost Considerations
Door hardware is a separate item that attaches to the door and may be simply to allow the door to operate and a handle to grasp. When considering door hardware be aware that the cost of door hardware may exceed the cost of the door three times over. Hardware may consist of hinges, pivots, handles, latches, levers, passage sets, privacy sets, locksets, panic devices, push/pull plates, closers, kick plates weather stripping, sound seals, dust seals, and peep sights to name some of the items.