Year: 2006

Location: Stuttgart, Germany

Country: Germany

Owner Builder: Häussler-Gruppe

Contractor: SKS BAU GmbH & Co. KG

Designer: KBK Architekten Belz Lutz Guggenberger

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Problem / Solution

The Carl Benz Centre is in the middle of the “Neckarpark”. It is a collective idea from the Häussler-Group and the soccer club VfB Stuttgart. The Carl Benz Centre consists of a 4-star-hotel with spa area and functional rooms for the VfB Stuttgart, as well as the underground carpark with overlying green roofing with 1.700m³ expanded clay. For the green roof was important not to oversize the structure of upper deck and should be a strong material.

Experience

Expanded clay find in the green roof is high resonance, because of balanced mixture between weight, toughness and water capacity, similarly to the substrate. The expanded clay mixed with the substrate reduces the total weight more than 20% and counteract the aeration of the green area, because of the good denticulation. In addition, the expanded clay is easy to fill and install with silo trucks.

Why expanded clay?

The low weight of expanded clay by high toughness allows us not to oversize the substructure, by a good force transmission. A high-water capacity up to 75 M-% was also need as a substrate material which is non-putrescible and airy. The first layer was only crushed expanded clay, as a drain- and reservoir-layer. While, the second layer was a substrate mixed with crushed expanded clay, as a culture medium for the plants.