The amount of coal used by residential buildings in China should be capped at 230 million metric tons by 2020, according to a report released by Beijing Jiaotong University.

"Green buildings and renewable energy are the right answers to improve housing energy efficiency in cities and rural areas respectively," Liu Jing, associate professor at the university, said.

Speaking at a workshop on a coal consumption cap held on Wednesday in Beijing, Liu said that 50 percent of newly-built houses in urban areas were expected to meet green building standards, while 15 percent of rural houses will have adopted energy saving measures by 2020.

Energy generated by biomass, solar, hydropower and wind will surpass the 100 million tons of standard coal in rural areas, added Liu.

Heating from coal burning in winter is one of the major reasons for air pollution plaguing Northern China.

Early this year, the country pledged to cut coal production capacity by 150 million tons in 2017, with the capital Beijing aiming to eliminate the use of coal by the end of this year.

Through transforming the heating system of existing buildings by 2020, 70 percent of houses in 26 cities in North China's Heibei, Henan, Shandong, Shanxi provinces as well as Beijing and Tianjin will adopt central heating fuelled by clean energy. Coal will only make up 30 percent of energy used for winter heating in rural areas in the above regions, according to Liu.