Check out this treehouse in Florence, Itlay. I love the use of space. Being a New Yorker for the past ten years, I have become totally pre-occupied with getting the most out of a small space. I'm also intrigued by any building that incorporates nearby trees. I'm deprived of nature!! Anyway, check out the floor plan.
Also, check out this link. http://www.treehotel.se/
IT'S A TREE HOTEL IN SWEDEN. They have multiple tree house units which you can rent hotel style for the night. They were designed by leading Scandinavian architects. Did I mention there is a tree sauna that fits up to 12 people? This is inspiring me to create a tree house room in my soon-to-be-realized inn located in Saugerties NY. So incredible. Ugh. My favorite one is the house that looks like a mirrored box floating in the trees. Do tree houses get cooler than that? I dunno. My older brother built this suite of three tree houses when I was a kid. Two of them were linked with a draw bridge. One of them was three stories high. It's a toss up for me. Ultimately, the floating glass box is more comfortable, that's for sure. haha. Enjoy your newfound desire for a modernist tree house!!