It being a facility for the general public, we thought it should be structurally safe and easy to explain, hence we decided to create an independent building not touching the tree. The site, however, was a steep slope inaccessible to heavy machineries, and the house would have to be established among complexly intertwined branches 10m above ground. Therefore, to enable construction by manpower using light structural members, we chose a composition employing square and hexagonal solid steel rods, 3cm in diameter.

Assembling the rods by connecting the surfaces, we constructed a truss held at two points. Using the structure as scaffolding, we assembled it by avoiding the branches as birds create their nest, adding or taking out components based on structural analysis. We mortared the room interior like a swallow’s nest. The design leaves open the possibility for visitors to experience nest building by branches from the mountain side and fitting them into walls inside. The exterior appearance and interior space have a gentle and comfortable atmosphere reflecting the bodily scale of the builders.

It is architecture assembled by intertwining components small enough to carry. The architecture can adapt flexibly to the tree form (as opposed to “site form”) and melts into the forest crowded with dark branches.