[darsham]

The frame and rafters seem solid (as long as you don't stress it too much), but it seems inevitable that the roots of plants will pierce the plastic layer, and rain will drain though the roof.

I know it's heavy duty plastic, but the roots of small plants can crack rock.

It's hard to tell from all these 200x200px pictures, but is the plastic the first thing on the ceiling? If that's the case, you might patch it up as it gets punctured or replace whole sections of it. I'm very curious as to how the house and vegetation will evolve on the long term, because this is pretty much my dream house.

Edit: After looking at the rest of the website, it becomes clear that they know what they're doing. I'm still curious about the details.