Another diagram of the numbered pieces...

As it is with what I'm actually using, probably could've gotten by with 2 sheets. Went ahead though and cut out the gingerbread trim and bagged it up... May yet be used elsewhere. Also, for my New Year's Eve, since I won't be spending with my guy -- treated myself to a trip to the hardware store. They don't carry MDF or particle board here, but they had 1/4" luan sheets 4' x 8' for $10. So that is what my room addition and entryway will be made of, don't think it'll be too bad b/c the kit wood's a bit thicker as is...