To keep the area of the built development to a minimum on this tight site and to allow a maximum of landscaping, large sections of the complex were sunk in the ground. The changing rooms and spaces for equipment are covered with earth, and the flat roof of the hall is also planted. The roof is divided by a tubular steel, triangular-section trussed girder, which creates a longitudinal roof light over the sports hall. Rainwater runs off from the roof light to the gutters at the edges of the roof and then through spouts in the peripheral upstand beams.?