Weburbanist has a great post detailing 10 amazing tree houses, including Free Spirit Spheres
and “grow your own” varieties. These latter, from a combination of scaffolding and other systems, could be used to direct the growth of concept tree houses over a period of years. Vines, roots and trees become organic architectural materials to create a flexible framework. Windows would be made of flexible soy membranes that would shift as the building grew.
Well worth checking out the full post for some real tree hugging fun.