A tower made of self-shaping wood

The Institute for Computational Design and Construction and the Institute of Building Structures and Structural Design at the University of Stuttgart worked together to design the Urbach Tower, a structure made of self-shaping wood.

The design of the tower relies on a new self-shaping process of curved wood components. Rather than energy intensive mechanical forming processes, the new technique allows for the wood to shape itself.

Wood shrinks when its moisture content drops, which can lead to cracking and deformation. However, this project uses this fact to the advantage. The wood is programmed and arranged in such a way that naturally occurring deformation triggers a designed self-shaping behaviour.

Methods for bending wood have existed for centuries (think of the hulls of boats), though most current methods still rely on brute mechanical force for shaping processes.

The team from the University of Stuttgart used computational simulations to predict how the wood would deform. They used flat Cross Lamented Timber (CLT) components for the tower’s structure, predicting the way they would shape. The spruce parts are produced with high moisture content and specific layups and CNC cut into shape. They were then dried in an industry standard technical drying process. When removed from the drying chamber, the parts are precisely curved. The parts are overlapped and laminated together to lock the geometry in place, forming larger curved CLT components with form stable geometry.

The tower consists of 12 curved components, cantilevering 14 metres upward, and sports a transparent roof. The curvature makes a lightweight and slender structure possible. Each of the parts is only 90 mm thick and has a protective layer of glue laminated larch wood and an inorganic coating that protects the wood against UV-radiation and fungi. The elements are connected by crossing screws.

Photos: University of Stuttgart