As housing vacancy rates rises indicating a worsening bubble in the property market, experts Wednesday urged the government to conduct a census to provide a more realist picture of the real estate sector.

Without a census, the government will still be unclear on how to make policy, said Zhu Zhongyi, vice-chairman of China Real Estate Association.

Zhu made the remark amid earlier reports that there are at least 60 million units of housing left vacant across the country.

An anonymous employee at the State Grid Wednesday told the Global Times that "we cannot get the figures of zero electric meters," without elaborating

The head of the Ministry of Housing and Urban-Rural Development, however, has admitted that housing vacancy is a problem.

But so far no government department has conducted a thorough census of the vacancy rates.

Teachers from Beijing Union University conducted a survey in 50 communities sold between 2004 and 2006 in Beijing and found that 27.16 percent of the electric meters did not move in 2007.

"The figures go higher as you move from the inner city, with the suburbs registering around 30 percent vacancy," said the writers of the survey quoted by 21st Century Business Herald.

Their figures did not include unsold properties.

The occupancy rate in new communities in Nanjing, capital city of Jiangsu Province, is nearly 50 percent, and in Hebei's capital city, Shijiazhuang, the rate is between 40 and 60 percent, said the report.

Experts attributed the vacant housing to a lack of investment alternatives as "people in China uses housing as store of value".

"Moreover, people may be over-optimistic, for they've never seen the housing market go down in the past years," Patrick Chovanec, associate professor of Tsinghua University's School of Eco-nomics and Management, told the Global Times

Chovanec added that the households in China have no property tax to pay, another reason leading to the high vacancy numbers.

If Chinese are given more investment channels and taxes are levied, they would not necessarily have to invest in the property market, advised Chovanec.