its tricky but once you get the hang of it, not that bad. you can get pure stone + iron beams up at least 4-5 floors, and pile wood on top of that another 3+. That is without a landspike sneaking support in, and you can do other screwy stuff too. you can make a set of landspike walls all the way around, put down rock floor as roof, and that is a finished basement and your house starts at level +1 or +2. The total has to be at least 10 floors if you mix land, stone, and wood all optimally. I get sick of walking up 3 flights of stairs, so that sort of project has been on the 'maybe if/when the game is released for good' table for me.

I have done the finished basement, took a lot of iron to get the rock flooring and I used a landspike in the middle. Its on the shore and I dug out for my boat too. I ran out of steam after the proof of concept, though.