I have a pretty small back yard, but I have a good tree house tree. My kids love to play outside — just like I did when I was a kid. And one of the things I always wanted as a kid was a tree house! I never got one, but I can build one for my kids.
So I did some planning, measuring, sketching, re-measuring, and re-sketching. Then I went to Home Depot to see what the standard sizes of wood were. I wanted to do as little cutting as possible. I ended up planning the base/floor of the tree house to be a standard length of a 2×6, which is 8 feet. Voila! No cutting to length!