Hello everyone. We recently had a query on how to model a 5" high "basement: that is totally unconditioned and has an insulated floor above. This, in HOT2000 would always be considered a basement as precedure tells us but would be considered a heated space. We asked the questions and the response from NRCAN to maintain the unconditioned area is as follows:

"Adjust the exposed surface perimeter of the crawl space so that the correct wall areas are accounted for within HOT2000's crawl space height limitation of 3.94 ft. This will result in a larger perimeter, a shorter height but the same total area."

Gilles Lesage

Angela, if you checked the "Over enclosed unconditioned space" that would make sense to me but I think the crawlspace method is more accurate.  It would be interesting to see the difference. I have a feeling using the crawlspace method that Gilles described and NRCan recommended would have slightly less heat loss because of the interaction of the main floor with the underground portions of the crawlspace.