I changed my mind, I'm no longer building a hut with a firepit in the centre.
Instead it's going to be living architecture.
I've planted willows around the outside that I'll guide under the roof as they grow, and wisteria vines that'll grow up each post then spiral into the middle.
I'm going to harvest some bigger willow cuttings and make a tripod in the middle grafting the trees together, eventually grafting the centre trees and outside trees into each other as supports for the wisteria.
Eventually the frame will fall apart or rot away and hopefully the living trees and vines will keep the shape.