Viewing tower with resource-conserving design

An innovative viewing tower was developed for the National Horticultural Show as part of a collaboration between project partners ICD University of Stuttgart – Prof. A. Menges, ITKE University of Stuttgart – Prof. J. Knippers, Wangen National Horticultural Show in Allgäu 2024, and Blumer Lehmann. As general contractor, we were responsible for the manufacture and constructional implementation of the structure, and we were also involved in development of the execution schedule and production methods.

The research project is the first accessible tower in the world to use curved wooden components made up of glued cross-laminated timber formed by the natural shrinking process of the wood. As a large-scale demonstrator, the tower should exhibit the innovative use of wood as a construction material at the National Horticultural Show. Made up of six prefabricated elements, the structure was erected in just three days. The height of 22 m and location on top of a hill posed a structural challenge. After all, the tower needed to be environmentally friendly and light in both its design and its materials, while at the same time, the construction needed to be capable of withstanding high wind loads.

Sustainability is also very much at the forefront with regard to the viewing tower’s footing, comprising a base area of 50 m²: the foundation is made of recycled concrete and cement produced with low CO₂ emissions. The rear-ventilated, 20 mm-thick exterior cladding consists of vertically mounted solid larch wood panels. The viewing platform is accessed by a steel staircase with 113 steps.