Official figures show that China has built 320 million square meters of energy-efficient housing in urban areas since 1986.

The Ministry of Construction says that the housing has helped cut energy consumption by over 10 million tons of coal, and therefore reduced emissions of carbon dioxide by over 20 million tons.

China started to encourage energy-efficiency in real estate and construction in 1986.

It's also made public energy-saving design standards for residential housing in northern areas, and set a target of 50 percent reduction in energy consumption.