This is an excellent video for anyone looking for treehouse building tips. It gives you a quick overview of how this team of professional builders erected this massive Oregon treehouse. It gives some insight into some of the problems they faced while building this treehouse and how they overcame them.
You also get to see the tools and fasteners they used and how they used them. Of particular relevance to any treehouse builder is the footage showing how to install the massive bolts that hold up the structural beams. Because this building is so huge, those bolts will have to carry tremendous loads.
The fact that there are only seven bolts on the bottom floor and five on the second floor testifies to just how incredibly strong those bolts are. Smaller treehouse designs would probably only need one, two or three of those bolts to hold the entire weight of your structure — and the people you plan to have in it.
All of the ideas are adaptable to smaller treehouse projects, though you might not bother with some of the higher end carpentry tricks like hiding metal fasteners inside wooden beams.
I must say that I was very impressed with the many ways the builders very skillfully used chainsaws as routers and circular saws. Do not try that at home unless you have your black belt in chainsawery!