Why is the property right of Langzhong house forty years?

Hello, my friend, I am a real estate agent in Shanghai. The answer is as follows: Generally speaking, the residential property right is 70 years. Commercial and residential: 50 years. Pure commercial land: 40 years. But local regulations are different. This is related to policy. There is no way that the state stipulates how many years it can be used at most, but it does not stipulate how many years it can be used at least. A little contrary to public opinion!