There are a lot of videos about empty aparment complexes and entire cities that have been built but are unoccupied. It seems many Chinese people who have made money in the expansion of their middle class do not trust other investment vehicles (their stock market for example) and turn to real estate as a place to park money.
The problem is, like all bubbles, the speculators who buy these properties hoping for high demand to force prices up are still waiting, and it leaves literally millions of square feet of unoccupied high rise properties waiting for tenants years after they were built. Sooner or later the bubble will burst.
I saw an article a while back that suggested the Chinese central bank and other major banks have been backstopping these developments in order to kick the can down the road, so to speak.
Search YouTube for "Abandoned Chinese cities" for more videos.