getting ready

After years of asking - especially after a trilogy of High School Musical movies - we're going to build a tree-house for the boys. We weren't planning on building one, but our back neighbor offered us his son's fort and it seemed like good material we could use. After some assessment with the tree out back, we decided it's feasible.
Another neighbor, who has maintained golf courses professionally, says the tree is a silver maple. He also says it was trimmed hard when it was younger which created many branches atop a large trunk. He didn't say the tree was unstable, but did say he felt better when he heard our plan to tie in only to the thick trunk. The goal is to build a mostly self contained platform and attach only two bolts to the actual tree, doing as little damage as possible. The second thought with the self contained platform is if one day the tree is no longer there, hopefully the tree-house can remain. Also, the tree-house is going to be big enough to be interesting into the teen years as well.
Borrowed a friend's truck to pick up supplies. Also received the zoning permit from the city in the mail. Just waiting on the starting gun. On your mark, set....