A Unique Landmark Built from Self-Shaping Wood Remstal Gartenschau 2019, Urbach, Germany
The Urbach Tower is a unique wood structure. The design of the tower emerges from a new self-shaping process of the curved wood components. This pioneering development constitutes a paradigm shift in timber manufacturing from elaborate and energy-intensive mechanical forming processes that require heavy machinery to a process where the material shapes entirely by itself. This shape change is driven only by the wood’s characteristic shrinking during a decrease of moisture content. Components for the 14 m tall tower are designed and manufactured in a flat state and transform autonomously into the final, programmed curved shapes during industry-standard technical drying. This opens up new and unexpected architectural possibilities for high performance and elegant structures, using a sustainable, renewable, and locally sourced building material. The Urbach Tower constitutes the very first structure worldwide made from self-shaped, building-scale components. It not only showcases this innovative manufacturing approach and resultant novel timber structure; it also intensifies the visitors’ spatial involvement and landscape experience by providing a striking landmark building for the City of Urbach’s contribution to the Remstal Gartenschau 2019.
MATERIAL PROGRAMMING AND PREDICTABILITY OF SHAPE CHANGE
In timber construction, moisture typically causes problems with cracking and deformation; hence, moisture changes and stress development must be carefully controlled. In contrast, in this project wood is programed and arranged in a way to utilize this powerful, naturally occurring deformation to trigger a designed self-shaping behavior. In the same way that machines can be programmed to perform different movements, wood parts can be programmed to transform into predetermined shapes when dried. While methods of bending wood into different shapes for structure and aesthetics have existed for centuries and have become recognized industrial processes, they still mostly rely on brute mechanical force for the shaping process. Similarly, an understanding of how wood deforms due to changes in moisture content is well known in practice and academics. However, a shift in design thinking, as well as new computational simulations for more accurate prediction, now allow us to use this moisture induced swelling and shrinking to design and program specific self-shaping movements at larger and larger scale.
- Bechert, S., Aldinger, L., Wood, D., Knippers, J., & Menges, A. (2021). Urbach Tower: Integrative structural design of a lightweight structure made of self-shaped curved cross-laminated timber. Structures, 33, 3667--3681. https://doi.org/10.1016/j.istruc.2021.06.073
- Wood, D., Gronquist, P., Bechert, S., Aldinger, L., Riggenbach, D., Lehmann, K., Ruggeberg, M., Bugert, I., Knippers, J., & Menges, A. (2020). From Machine Control to Material Programming: Self-Shaping Wood Manufacturing of a High Performance Curved CLT Structure -- Urbach Tower. Fabricate 2020: Making Resilient Architecture, 50--57.
- Aldinger, L., Bechert, S., Wood, D., Knippers, J., & Menges, A. (2019). Design and Structural Modelling of Surface-Active Timber Structures Made from Curved CLT – Urbach Tower, Remstal Gartenschau 2019. Impact: Design With All Senses Proceedings of the Design Modelling Symposium 2019, 419--432. https://doi.org/10.1007/978-3-030-29829-6 33
- Grönquist, P., Wood, D., Hassani, M., Wittel, F. K., Menges, A., & Ruggeberg, M. (2019). Analysis of hygroscopic self-shaping wood at large scale for curved mass timber structures. Science Advances, 5(9), Article 9. https://doi.org/10.1126/sciadv.aax1311