Use this procedure to miter the corners where door/window assemblies meet. The corner where adjacent door/window assemblies meet is not mitered by default. However, you can automatically determine the necessary angles.
The miter angle applies to all infills and horizontal edges (frame or mullion) that are adjacent to the corner. Vertical edges are not affected.
Tip: If you want to create a custom corner condition between two door/window assemblies, you can replace the edge of one door/window assembly with an AEC profile and remove the edge of the other door/window assembly by using the frame override Remove Edge option.
- Select one of the door/window assemblies.
- Click
. 
- Select the other door/window assembly.
If you change the angle of either door/window assembly, use Set Miter Angles again to recalculate the angles.