Just reading up on some old material. From Koolhaas' Greap Leap Forward back in 2001:

"Chinese architect: the most important, influential, and powerful architect on earth. The average lifetime construction volume of the Chinese Architect in housing alone is approximately three dozen thirty-story high rise buildings. The Chinese Architect designs the largest volume, in the shortest time, for the lowest fee. There is one-tenth the number of architects in China than in the United States, designing five times the project volume in one-fifth the time, earning one-tenth the design fee. This implies an efficiency of 2.500 times that of an American architect."

"Factory/Hotel/Office/Housing/Parking: The status of all floor space in the PRD (Pearl River Delta) is generic. Each programmatic function is provisional, and every occupancy is only temporary."

I don't think much has changed since then. If anything, the numbers must be even more staggering now.
_______

Alex Pasternack, a colleague, has a good article about the state of "green architecture" in China. In essence, not many buildings being built today meet basic sustainability standards, and the industry and government is still vague on green strategies.