It is not lack of wood. Check the population, both at country level and at city levels. Take a look at China in Google Map or Google Earth. If you would like to do research a little further, check the areas covered by forrest. Then you might get an answer.

A little historical perspective would help as well. Check how many houses are made of wood in New York City. A reminder: a large number of cities in China have a longer history than New York City.