Du said one of the most expensive apartments in the Lujiazui area was priced at more than 90 million yuan ($14.57 million) excluding decorations and amenities.

Many of Shanghai's richest have properties in the Lujiazui and Xintiandi areas. The average property price now stands higher than 70,000 yuan per square meter in many of these compounds, which have easy access to supermarkets and schools, and command impressive views. Prices at some residential compounds could reach 200,000 yuan per sq m, but transactions in these are not as active as those under 100,000 yuan per sq m.

Suburban villas remain popular among billionaires in Shanghai amid increasing concerns over urban air quality.

Transactions of more than 80 million yuan often take place in Songjiang and Changning districts, two traditional villa hubs which boast the freshest air and highest forest coverage rate in the sprawling city. In September 2014, a 120-million-yuan villa was purchased in Sheshan, Songjiang district, near botanical gardens and a national forest park.

Mounting awareness of pollution and air quality issues have also affected the high-end housing market for foreigners, which accounts for a significant share of the city's high-end residential market.

"Serviced apartments are among foreigners' first choice when considering a residence," said a research report by realty services provider DTZ East China.