CSCEC + PTW + CCDI and ARUP won the International Design Competition for the Beijing 2008 Games aquatic centre. The scheme meets international standards for competition, while maximising social and economic benefits. In addition to being an aquatic competition venue for the games, the centre will provide public multi-function leisure and fitness facilities before and after the games.The concept combines the symbolism of the square in Chinese culture and the natural structure of soap bubbles translated into architectural form. The design uses state-of-the-art technology and materials to create a building that is visually striking, energy efficient, and ecologically friendly.The striking Watercube structure will be energy efficient by maximising natural light and capturing solar energy to heat the interior spaces as well as the pools. Water efficiency will be achieved by rainwater harvesting, recycling, efficient filtration and backwash systems.PTW’s role involved concept design and design development.The National Swimming Centre (Water Cube) for the Beijing Olympic Games 2008 sets standards for a new generation of globally sustainable buildings on a world stage.The exterior of the building is made up of a transparent dual-ETFE cushion envelope (ethylene-tetrafluoroethylene), like bubbles, allowing the WaterCube to achieve great thermal efficiency. The envelope is so well insulated that the design may create an annual net heat gain. The concrete structures containing the pools will act as thermal masses, retaining heat during the warm days and releasing it over the course of cool nights. This system will cause the envelope to function much like that of a giant greenhouse, reducing the energy consumption of the leisure pool hall by 30 per cent.The envelope has three modes of operation, allowing the building to adjust to winter, summer and mid-season conditions. These changes are achieved by varying the amount of light and solar radiation entering the interior, by varying the translucent and transparent foils. Hence, the level of natural daylighting is controlled and altered easily diminishing the need for artificial illumination during daylight hours, therefore achieving up to 55 per cent savings on lighting energy in the Leisure Pool Hall.The Watercube captures the swimming pool water for reuse. After leaving one of the main pools, the water passes through a secondary filtration system and then enters an exterior conditioning pond on the site. Here the water is treated and allowed to settle out before being returned to the pools.In addition to the recycled water, collected rainfall in underground tanks is used as a back-up water supply. The advantage to this system is two-fold. First, this system minimizes the pools impact on Beijing’s wastewater system. Secondly, this approach ensures the necessary water levels for the pool, especially for the crucial Olympic events, regardless of the regions sporadic rainfall and risk of low water levels.