The concrete roofing is designed as the intersection of three circle-shell slabs with thicknesses ranging from 140 mm to 200 mm. Each shell slab is at its centre supported by a cone-shaped column. In order to drain rain water, the columns are tubular. On the bottom side of the shell-slab is a small groove for the lighting. The steel reinforcement is made of bars, with diameters of 8 mm and 12 mm. Waterproof concrete (Class C30/37) was used to provide protection against rainwater. The foundation is a combination of foot flange and foundation straps. The external column diameter is 550 mm, the internal 200 mm. The circle shell slab diameters are 10 m and 8 m. The total construction height is 8 m (5,500 mm above the ground level; the foundation is 2,500 mm high)