Designed by Pritzker Prize-winning architect Frei Otto along with Carlfried Mutschler and Joachim Langner, the Mannheim Multihalle created a revolutionary precedent in organic architecture upon its completion in 1975. Created for the Bundesgartenschau (Federal Garden Exhibition) in Mannheim, Germany, the building features an extraordinary, double-curved flowing canopy that spans over 9,500 square meters without a single internal column support. The secret to this breathtaking span lies in its timber grid shell technique.
Constructed using simple, slender hemlock laths measuring just 5 by 5 centimeters in cross-section, the grid was initially assembled as a flat mat on the ground. Using a system of scaffolding towers and winches, the entire flat timber network was carefully pushed and lifted upward, forcing the flexible wooden strips to bend, twist, and deform into a double-curved shell form. Once the desired shape was achieved, thousands of bolt joints at the intersections were tightened, and diagonal wire ties were added to fix the structure into a rigid, highly stable three-dimensional form.
Otto utilized physical hanging string models to calculate the ideal compression-only shell form long before modern computer-aided structural analysis was available. Although intended only as a temporary structure to be dismantled after the exhibition, the Multihalle was recognized as a historic architectural landmark due to its structural brilliance. Today, it stands as an enduring masterpiece of lightweight structural design and sustainable timber engineering.