Virtually all tree houses are made out of materials that are not growing. The tree is. If the tree overgrows the structure, the structure will kill the tree even if it is wood itself. Without proper maintenance to trim back the structure from the tree, how is that sustainable? How is it sustainable at all?

Living in tree houses IS fun though....

I can envision a tree house that uses cables strung from limbs with woven flooring , a system that sways with the tree and allows for the growth of the tree. It would best work in temperate climates but is not technically restricted to them ....where the cable is wrapped around the limbs would of course require inspection. You could use steel cables or even woven natural fiber ones though those would require closer inspection on a more consistant basis...this model doesn't lend itself to restrictive binding construction though all aspects would have to incorporate sway give from wind...it wouldn't be for everyone...the elderly would have the hardest time I would think....

Check these..

freshome.com/2008/01/08/...tree-houses/

Thoughts on this thread: There is already some technology out there that adjusts as the tree grows. I don't know anything about it, I just heard some enthusiastic arborists talking about it once. A tree house almost as a rule, is going to have a limited lifetime because of the tree. Trees get sick, blow over etc.. I can't personally imagine a house in a tree that would help prevent any of these problems. Are there any real advantages to living in a tree house? I think it's just neato basically.

10,000 canoes was Ok, but don't watch the stone tool making scenes as they are all wrong. Some of the props and weapons were pretty cheesy too. So what if they were stripping the bark off trees? It's all about the context in which they were doing so isn't it? Where I live I've got trees coming out my ass (now that's sustainable!). I can't wait till I have the time and energy to bust out my chainsaw and start thinning and trimming. Most of my "extra" trees are small diameter firs and hardwoods, there are millions of acres of this stuff.. a legacy to decades of logging. So, I am interested in building with poles. If I lived where there were Eucalyptus growing I'd be all over stripping their bark and killing them because they are extremely invasive and don't allow anything else to grow beneath them. Let's use them for something! These are local solutions to local problems. Yes there are too many people for everyone to strip bark from trees to make tree houses, but that can be irrelevant to a local situation.

People consume period. You have some choice about what you consume and it behooves us all to take into account many factors when making these decisions. If when making decisions of this nature we take an intensively resource based view of our situations through the lense of a value system based on long term sustainablity and happy people, we are more likely to make good ones. That mindset is going to tighten the lasso of resource consumption in as locally as possible.

I'm continually shocked and disappointed that people have to latch onto what seem like simple solutions, or bash others without looking at the big picture. Ok, so bamboo can be sustainably harvested in asia where it is more native. That doesn't mean we should ship 90,000,000 pounds a year to America for our pimpy bamboo floors and fences in our "green" remodels. We need more local solutions and, as a society, are really exhibiting a failure of creativity in this regard.

And it always comes down to the same problem. There are way too many people to maintain a high living standard for everyone. No reallocation of resources, newly discovered super plant, alien intervention, new building technique, free energy technology or whatever is going to fix that problem. Don't build a nursery in that tree house and it'll be that much smaller. Ok, so that was roughly on topic:)

"Keep your dreams alive. Understand to achieve anything requires faith and belief in yourself, vision, hard work, determination, and dedication. Remember all things are possible for those who believe." - Gail Devers

www.archinode.com/bienal.html

From the website
Principles:

This home concept is intended to replace the outdated design solutions at Habitat for Humanity International. Our goal was to propose a method to grow homes from native trees. This enables these new local dwellings to be a part of an absolutely green community.

1. Composed with 100% living nutrients.
2. Harmonize & embrace growth.
3. Make effective contributions to the ecosystem.
4. Accountable removal of human impacts.
5. Involve arboreal farming & production.
6. Subsume technology within terrestrial environs.
7. Circulate water & metabolic flows symbiotically.
8. Consider the life cycle, from use to disposal.
9. Achieve a fitness with our earthen web of life.