The shape of this house in the trees was inspired by the Fibonacci Spiral. That's the spiral found in plants and animals like the sunflower and the snail's shell (see video from below). The building, by Blue Forest, is made from sustainably managed forest timbers using laminated ribs for the framing which is clad inside and out with larch boards. Larch has similar characteristics as oak but is much cheaper.
The tiny house is 25m2 (270 ft.sq.) with a small kitchen and space for a bed and chairs. Once the frame of the house was made off-site it took a small team of builders about 8 weeks to construct. It's a bit of a kid's paradise with 40m (130 ft) of rope bridges and a 23m (75 ft) slide.