The central government is urging its branches at all levels to avoid constructing public buildings that are peculiar shapes in a bid to cut down on energy consumption.

A statement jointly issued by the Ministry of Housing and Urban-Rural Development and the Ministry of Finance on Wednesday points out that energy consumption per square meter of public buildings must be cut during the coming years. The government plans to slash energy bills by 10 percent during the next five years for regular buildings and 15 percent for large public buildings.

However, energy consumption in large public buildings is still increasing sharply, the Ministry of Housing and Urban-Rural Development said on its website.

Buildings that are strange shapes are especially expensive, costing more to light, heat and air condition.

"A large number of new buildings that are odd, peculiar shapes are being added annually, especially in small cities and counties, because many local authorities emphasize creativity," said Zhang Xin, an architecture professor at Tsinghua University. "But buildings that are peculiar shapes have much higher energy consumption than ordinary ones and most people are not aware of that yet."

In a recent case, the design for a 150-meter-tall building shaped like a table-tennis bat was unveiled in Huainan, Anhui province. The total investment will be 300 million yuan ($46 million), local media reported in April.

The statement from the ministries also said some cities will be chosen to pilot energy-saving buildings in the next five years.

The central government will give the cities subsidies of 20 yuan per square meter, the statement said.

"The country had great difficulties in promoting energy-saving buildings in the past, partly because of the high cost of energy-saving building materials," said Li Chang'an, a public policy professor at the Beijing-based University of International Business and Economics.

"Sufficient subsidies and other preferential policies should be offered by the central government, otherwise developers are likely to raise house prices when their construction costs become higher."

At present, 30 percent of the country's total energy consumption is gobbled up for the daily operation of buildings, according to the Ministry of Housing and Urban-Rural Development.