This model looks really fantastic, but wouldn't the house block light from trees below it?

I agree with the above comment, wouldn't this block the light from the trees below the housing complex, also would this be at all practical in areas where there are no trees, or is the idea that forests would be grown with the intention of being partially housing areas? in this case it would not be very amenable to wildlife, which is the primary reason, in my opinion, for the maintenance of areas such as this. I think that in a concept world, this is a wonderful idea, however in reality I just don't know how it could happen.

It would certainly create some shadow to the trees below, but I doubt it would be the kiss of death. The earth rotation would mean that the shadow would move around, and even something in a direct shadow receives ambient light (after all, grass still grows on the north side of houses).

How would you get into the house if you were carrying say, a load of groceries? A wind-powered several-story elevator? I enjoy the inventiveness but the idea seems flawed; instead of avoiding environmental damage by building above the forest, eliminate the problem at its source and avoid building in the forest to start.

Apparently they're not bothered by falling trees in the UK.

Building homes in rural Washington State, the big problem was Alder trees and other trees with shallow root systems being blown over in a storm. You had to clear away all your Alders before you could build.

Also, what is it about me: plastic just doesn't seem to go with trees

You guys are all a bunch of negative Nancys. I for one love the idea of living in a tree house. If you go shopping in your 15 mpg suv, this is not the house for you...
Underneath the house, you can plant growth that thrives in shady conditions.
It looks pretty sweet to me, I`ll probably still build my own using local materials with lower embodied energy.

I wouldn't be so big on looking at that during my forest hike.

Another concern that should be addressed in many areas is wildfires. In some regions you are required to clear trees within a certain range of the house due to building codes due to the hazards of wildfires. More areas recommend it than mandate it. Regardless though as someone already pointed out you could still plant other forms of vegetation or shade plant in the areas around or near the house.

Another place though that this may have practical application is in areas where the ground below is irregular or very steep and would otherwise be prohibitive to build on without a lot of excavation/construction.

Don't worry - the cost to build such a structure would be all but out of reach except for the very very rich. The cost of the foundation would be extreme. There's a reason housing is built the way it is - it's AFFORDABLE. If we want to live in the trees it can be done, but at a serious expense. If you think about it, the cost to do this kind of work will be far more expenseive than a luxury condo tower, where you have the efficency of building similar units one on top of the other with shared structure and utilities. This simply building the penthouse ALONE... I'd love to see the offering price