Half of China's current urban houses will be dismantled and rebuilt over the next 20 years, China News cited a scholar with the Ministry of Housing & Urban-Rural Development (MOHURD) over the weekend.

Chen Huai, director of policy research center under MOHURD, made the remarks Saturday in a rural reform forum held in Hainan Province.

The houses that need to be demolished include slums and very old houses built between 1949 and 1979 that are not earthquake-proof. Houses built between 1979 and 1999 by some State-owned enterprises for their employees are not well-designed and also need to be demolished, he said.

Chen overestimated the percentage and should consider different situations of each city, said Liu Weixin, vice president of the China Society of Urban Economy.

The overall percentage nationwide is between 25 and 30 percent, Liu added.

"Around 90 percent of Beijing has already been demolished and reconstructed," Liu said. "Demolition and relocation could take place in some second- and third-tier cities with old houses built in the 20s or 30s, but it shouldn't be done simply for the purpose of demolition."

Expenses and real demand should be taken into consideration, Liu said, noting that it's not necessary to tear down all old houses.

The demolition and reconstruction will drive up the gross domestic product growth, however, without creating real social wealth, Liu said.

Liu agrees that the demolition and relocation will also lead to even higher costs of housing construction, driving the property market into even greater bubbles.

"Large scale demolition and relocation will also lead to a huge waste of resources and heavy pollution," said Niu Qian, project manager of Green and Ecological Building Research Center under China Academy of Building Research.

She suggested that only houses posing danger to the habitants should be demolished.

"Even for those houses to be torn down, the government should set high standards for the property developers able to take energy-saving measures and ensure the sustainability of the new buildings.

European buildings could stand for about one hundred years, why can't Chinese buildings?" Niu asked.

Chinese buildings last only 35 years on average, according to MOHURD.