Well, I don't understand the technical part of this, but I thought that this maybe just can serve as an inspiration...
I wonder if the parts can be made from willow and put together like constructing a big basket??? and around maybe straw - strawbales???
Ok, I know that this version can't be finished in a few hours like the one in the video, but it can be cheap (this one is very expensive around 50 000$ for 44m3),
and much more ecological - made from local materials