DannR That's not currently possible, NCH Software formally takes suggestions or feedback about our products through the form at http://www.nch.com.au/suggestions/
David_Cooper I did dormers on mine! I just selected the next floor (4th in my case) and drew the walls for the dormers. Took some time to determine the wall heighth so the back side would be just above the 3rd floor roof, but it worked.