For single or pair doors.
After finished floor.
Width: Interior opening of the frame + 3-1/2″ (89 mm).
Height: Interior opening of the frame + 1-3/4″ (44 mm). /
Ex.: For a 36″ x 84″ interior opening (914 mm x 2 134 mm)
rough opening should be :
Width, 36″ x 3-1/2″ = 39-1/2″ (1 003 mm)
and Height, 84″ + 1-3/4″ = 85-3/4″ (2 178 mm).