This is after a multi-year contraction in housing/GDP. In 2013 housing contributed 22% to China GDP, which is about the same as in Spain and Ireland in 2007. This dropped to 19.8% in 2014 and to 15.1% in 2015. (Maybe 6% is something to aim at as a longer-term healthier number?)
This recent surge reminds me of what happened in Singapore, where we happened to be living during the Great Recession. The stock market went down and housing prices went up. The Chinese, who think multi-generationally, regard property as an investment and stocks markets as speculation. When they become leery of stocks, they buy property. In normal times Singaporeans speculate on stocks during the week and gamble on mahjong during the weekend. (In the local convenience stores the thick weekly books of stock charts are hot sellers.)
Here is a quote from the article: "'Leaving my money in the bank is meaningless and it will only devalue,' said Wang Hong, a 35-year-old office administrator who is looking to buy a second home in Nanjing." Holding fiat currencies is not considered a safe investment in Asia, where they do not benefit from the US dollar's strict stewardship.