This is maybe the best Library Object I've ever created.  It will cut a hole in the surface layers of any wall.  There are 2 ways to use it:   1:  Click and Drag in a 3D View - creates a rectangular hole in the surface layers of that side of the wall. 2.  Single Click in a 3D View - removes all surface layers of that side of the wall.   Note:  The Hole can be selected in a 3D View and edited basically like any Polyline.  IOW, it can be reshaped, filleted, moved, broken and stretched, etc.