After connecting the tables, I got the computer desk stand up part and laid it down with more hot glue. I have used this big wooden piece for several of my layouts. I suggest you secure one from your local dumpster or place of work. This shot is actually before I pulled the tables apart and connected them with the doweling rods.
After securing the the wooden piece, I laid down the base flooring, which is foamboard pieces. I had to buy some new ones because some of the ones I had were warped. They get all wavy after you spray paint them.
After the base flooring is laid down, I put down the side building that would become the "bunkhouse." It kind of looks like a cinder block, but it is a wooden box that I got from a thrift store. It had metal dividers and the lady at the store said it was "magic trick box." It was painted blue and had really crappy stars and rabbits painted on it. Stone texture spray paint covered it up nicely and goes over the wood grain to make it look just like concrete. I added the Tech Deck stair pieces to access the eventual roof. They are not affixed to allow access to the rooms. The "L" shaped wall in front of it is the drawer holder from an old BBQ grill, spray painted.