Hi Greg! Welcome to the forum!
I take it you have gone through the Archetectural tutorials within the program, and want to set up for some Printing?
One of out team members is fantastic @ the Architecural part, and I played with one of his cabins as a STL file.The resultant that I experienced, was very labor intensive, I haven't played an Architectural project for my own testing, but I would first go to converting all needed walls as solids,and set up an extruded surface to split the 'hole' in the wall. I'll take a quick look, and see what comes up!