(A)  The size doors required will relate directly to the size of your rough (framed) opening. The rough opening is a framed opening in a wall where your door unit will be installed. The openings are built slightly larger than the door frame to allow room for installation. We recommend that you add 2” to the door width and 2 ½” to the door height to allow room for proper door installation. This will compensate for width of the door jamb and the necessary shimming required to attain a state of level, plumb, and square. An example, using a 6/8 (80”) height by 3/0 (36”) wide door, your rough opening will need to be 82 ½” tall by 38” wide. Standard doors come in heights of 6/8 (80”), 7/0(84”),7/6 (90″)  and 8/0(96”). Most door companies limit the width of a single door to 42” maximum, to eliminate warping and cracking of the panels. The need for anything wider is easily filled by a double door unit application.