Use "wall offset" for wall area that is exclusive of the main portion of a room. (Example: for a 5'-0" x 7'-6" closet add the closet depth twice [5' + 5' = 10'] then enter '10' in the offset field). For a 5'-0" wide hallway that is open on both ends (no walls) deduct for "no walls" by entering '-10' in the offset field.
Try it with known quantities and view results. |