Measurement Guide

ROUGH OPENING OF THE FRONT DOOR
The next size is the Rough Opening size of entry door which the 2nd largest dimension and typically widely
talked about when referring to a new construction. The Rough Opening is the space between the two wall
studs the door unit will be attached to.
The Rough Opening is typically about 1-1/2” wider than the unit size and about a 1” taller.
The space that is left over will be used by the installer to shim and square the unit into place. Example 39” x 82-
1/2”. The recommended unit size for the opening would be around 37-1/2 ″ x 81-1/2 ″ which would leave a slab
size of approximately 36 ″ x 80 ″
UNIT SIZE OF THE FRONT DOOR
The Unit Size is the Door Slab WITH the FRAME . If the door comes with sidelights or a transom, they should
be included in the unit size. This is the dimension we need to determine if a project is eligible for an in-stock
door, or what dimensions we need to send to the factory to build a custom unit.
The unit size always needs to be smaller than the rough opening and brick opening and there needs to be
enough room around the unit to shim and level it into place. We recommend that the unit size be around 1-
1/2 ″ more narrow and 1 ″ shorter than the Rough Opening, but every builder might do things a little differently.
WE WILL ALSO NEED THE JAMB DEPTH TO CREATE A FINAL ORDER. This is the thickness of the walls. Thick
jambs can add significant cost or complications to an order. Some openings with standard door slabs can have
exceptionally thick walls that drive up the cost. The jamb depth must be determined by the person who will be
installing the door.