Wood, steel and fibreglass are common materials for exterior house doors. The doors must close securely, open smoothly, and serve as a barrier to weather extremes. Exterior doors are available in stock or custom sizes.
The standard size for an exterior door is 80 inches (6 feet, 8 inches) by 36 inches (3 feet). Stock exterior doors are also commonly available in 30 and 32-inch widths. The standard door thickness is 1 and ¾ inch. Some door manufacturers carry stock doors in 7-foot and 8-foot heights and door widths from 24 inches to 42 inches.
Patio doors are constructed of glass with a frame. The standard size is 6 feet, 8 inches tall and 6 feet wide. However, patio doors are routinely available in 6-foot, 11-inch and 8-foot heights.
Custom doors are available in many sizes. Doors often have a core of foam insulation and can be left- or right-handed, depending on the location of the doorknob. Doors are purchased as a slab (the door only) or pre-hung, a door mounted on hinges and attached to a door frame.