The Shanghai real estate market went into a frenzy yesterday when 1,706 units of brand new residential properties were put up for sale. Every single property was sold within 24 hours. The surge of online transactions even led to network congestion on the city's housing contract filing system.

Last week, the average daily trading volume in Shanghai (including affordable housing) was only 800 units. Analysts said that yesterday's sudden surge indicated a sort of "last chance" mentality among many buyers.

In fact, Shanghai will unveil several revised policies today in a bid to cool the city’s overheated housing market. The stricter policies are a response to the government’s concern that an increasing number of residents are unable to cope with constantly rising prices.

The government will be stricter in defining whether or not a property is the buyer’s first home, and may raise the qualifications for non-residents to purchase a house in the city.

Possible new measures include a minimum 70 percent down payment for second-time home buyers if the property is defined as non-normal, or a minimum 50 percent down payment for second-time buyers who buy normal houses, Caixin magazine reported on its website.

In Shanghai, normal homes are those no larger than 140 square meters and priced at less than 4.5 million yuan (US$ 691,000) within the Inner Ring Road, below 3.1 million yuan between the Inner and Outer Ring roads, or below 2.3 million yuan beyond the Outer Ring Road, according to Shanghai Daily.

All second-time home buyers are currently required to pay a minimum 40 percent down payment no matter if they are buying normal or non-normal homes.