In Graz a new complex of buildings in a very modern design is under construction for APG Allergosan Pharma GmbH. For the warehouse building with 2,185 m² of floor area, the company has chosen a wooden roof structure for its sustainability, performance and aesthetics. The Kielsteg elements used to form the roof are used here purposely as a secondary structure resting on a classical steel-reinforced concrete primary structure. The wooden elements used at Allergosan represent a new structural concept that concentrates material efficiently exactly where it serves the customer’s functional demands. This efficiency pays off handsomely. Since the elements are able to span 13,3 metres, the warehouse structure only needs two truss axes and four posts.