Chongqing is growing very rapidly, with well over a million people moving there annually. Clearly, the city needs to expand in an intelligent and efficient way in order to accommodate the population. This design for a green central business district was presented by CEBO/Chongqing University for the CO-EVOLUTION exhibition in 2006. The skyline of the community mimics the natural mountainous geography of the area, and the homes are arranged accordingly: at the tops of the mountains are modern residences, while more traditional Chinese neighborhoods are located in the valleys. The open green spaces are home to energy generating and water recycling initiatives. The designers say that the energy-saving mountain design can reduce overall energy consumption by 22% and replace 11% of energy from traditional sources with energy from renewable sources.