How do you know whether the property right of the downstairs house is a shop or a commercial house?

You can go to the developer's sales office to check the pre-sale certificate. If there is a record on it, you can also go to the Housing Authority to consult the staff. They have records there.

Commercial and residential buildings refer to comprehensive buildings for commercial and residential use. The ground floor (or floors) of general commercial and residential buildings are shopping malls, shops and businesses, and the rest are residential buildings. Commercial and residential buildings are not divided into construction subjects, which can be built not only by developers, but also by non-development enterprises and individuals. There is no requirement for sale. Commercial and residential land is a comprehensive land with a service life of 50 years.