My children asked me to build them a tree house, so trying to keep the work to a minimum I built them a large platform in one of our trees.  This kept them happy for  while, but eventually they asked for the whole thing to be made into a house.  I compromised and made a house covering half of the platform.  These are the photos of the job so far.

They are asking for a door and windows, so my work is still a little way off finished.  I have given all of the wood a good coating of water proofing, but I also want to cover the roof in felt to give it a bit more protection.