Cape Town Stadium

Erected for the 2010 FIFA World Cup, this circular building—with its curvy contours and an outer skin of fiberglass fabric that changes with the light conditions—forms a triad with the plateau of Table Mountain and the peak of Signal Hill. The arena appears smaller in scale than it is because it is set within a podium. Three grandstand tiers, whose upper edge undulates significantly due to the circular geometry, offer seats for 68,000 spectators. The roof, which is suspended from the slightly undulating outer compression ring, has been weighed down with glass roof panels to counteract wind suction and has a double curvature to guarantee that the construction is highly rigid despite its light weight and to help drain the rainwater from the heavy downpours typical of the region. The 36,000-square-meter roof area has been fitted around the outside with translucent laminated glass to protect against direct solar radiation, while the 16-meter-wide inner ring features clear glass to allow sunlight to reach the turf on the field. The cable-supported trussed roof structure with glazing weighs a total of 4,500 tons and is a highly optimized lightweight construction.