The 23-metre-high observation tower on the grounds of the 2024 State Garden Show in Wangen im Allgäu is an architectural highlight and landmark that was designed and built by the University of Stuttgart.
The Institute for Computer-Based Design and Construction (ICD) at the University of Stuttgart is known for innovative buildings that use state-of-the-art digital planning and production technologies. The tower is an impressive example of innovative architecture created using computer-based design methods.
The observation tower consists of twelve load-bearing, curved cross-laminated timber segments, which together form a surface-active timber structure. This construction not only makes it possible to effectively bear the horizontal wind loads, but also gives the tower additional stability. Inside the tower, a centrally positioned staircase spindle ensures that the vertical traffic loads are safely absorbed.
Particularly impressive is the use of local spruce wood, which is automatically formed into the desired shape through moisture-induced shrinkage. Inspired by natural biological models, this shrinkage of the wood is not seen as a disadvantage, but is used specifically as a design tool. During the controlled drying process, the moisture content of the wood decreases, resulting in the specified target curvature and giving the tower its characteristic shape.
The cross-laminated timber (CLT) used was manufactured using a special process consisting of double-layer panels. These boards consist of a 30 millimeter thick “active” layer and a cross-laminated, ten millimeter thin “restrictive” layer. The “active” layer, which has a higher moisture content, is glued to the “restrictive” layer in a flat vacuum press. After this lamination process, the flat panels undergo a precisely controlled drying process in which the “active” layer shrinks perpendicular to the fiber direction so that the panels bend themselves into the calculated shape. Finally, three of these curved double-layer panels are overlapped and bonded with an elastic barrier layer to produce stable, dimensionally stable and precisely curved CLT blanks.
Thanks to the use of state-of-the-art CNC milling technology, the digital model of the tower could be transferred directly to the wooden components. This optimized both the statics and production, while at the same time significantly reducing material waste. The twelve main components and the 168 larch wood panels for the façade were pre-assembled on site, allowing the tower to be fully assembled in just three days.
This innovative construction project was realized by a team from the Cluster of Excellence “Integrative Computer-based Design and Construction for Architecture” (IntCDC) at the University of Stuttgart. The team consists of experts who are characterized by their interdisciplinary cooperation and in-depth knowledge in the fields of architecture, engineering and digital manufacturing.
The Institute for Computer-Based Design and Construction (ICD):
Prof. Achim Menges
Martin Alvarez, Monika Göbel, Laura Kiesewetter, David Stieler, Dr. Dylan Wood
with the support of: Gonzalo Muñoz Guerrero, Alina Turean, Aaron Wagner
Institute of Structural Engineering and Structural Design (ITKE):
Prof. Jan Knippers
Gregor Neubauer
Blumer-Lehmann AG:
Katharina Lehmann, David Riggenbach, Jan Gantenbein
with Biedenkapp Stahlbau GmbH
Markus Reischmann, Frank Jahr
City of Wangen im Allgäu:
State Garden Show Wangen im Allgäu 2024
Other project participants:
Scientific cooperation:
Professorship for Forest Utilization Prof. Dr. Markus Rüggeberg, TU Dresden
Other consulting engineers:
wbm Consulting Engineers
Dipl.-Ing. Dietmar Weber, Dipl.-Ing. (FH) Daniel Boneberg
Collins+Knieps surveying engineers:
Frank Collins
Schöne Neue Welt Ingenieure GbR:
Florian Scheible, Andreas Otto
lohrer.hochrein Landscape architects DBLA
Building permit:
Test engineer: Prof. Hans Joachim Blaß, Karlsruhe
Experts: MPA Stuttgart, Dr. Gerhard Dill Langer, Prof. Dr. Philipp Grönquist
Cooperation for foundation:
Fischbach construction company
Project funding:
DFG German Research Foundation
Zukunft Bau – Federal Ministry of Housing, Urban Development and Building / BBSR
Discover the observation tower at the 2024 State Garden Show in Wangen im Allgäu and experience for yourself the extraordinary architecture and advanced technologies that make this building a masterpiece.












