Ok, so far the structures are almost done. I just need to add a couple little details like support beams for the tree boat house. Originally, I had the tree house look like a generic-looking house you'd find in a child's backyard. I didn't know which drawing I wanted my cooking hut to be based on, but after combining different elements from all of them, I'm pretty pleased with this one. The style for these structures are a mix between oriental and tribal/native- there's a lot of angular, sharp elements, combined with solid, linear components such as the wooden beams and piers.
*Update* 10/21/09 8:01 PM
Added more screenshots. Now with occlusion.