Is there an underground garage where you can buy a second floor?

There will be no rebellion in this situation.

At present, an independent drainage system is usually designed on the first floor, and the second floor is responsible for the drainage from the second floor to the 18 floor. The drainage pipeline will be inclined to provide a certain pressure for daily use, so that the drainage can be normal and there will be no water reflux on the second floor.

However, if the drainage pipe is blocked or the house has a long life and there is no property management, then there is a greater possibility of anti-water on the second floor.