For single or pair doors.
After finished floor.
Width: Interior opening of the frame + 2-1/4″ (57 mm).
Height: Interior opening of the frame + 1-1/8″ (29 mm). /
Ex.: For a 36″ x 84″ interior opening (914 mm x 2 134 mm)
rough opening should be :
Width, 36″ x 2-1/4″ = 38-1/4″ (972 mm)
and Height, 84″ + 1-1/8″ = 85-1/8″ (2 162 mm).