First: if there is no land use right certificate, no application for land use, or the land management department has not filed for registration, it can be considered as an illegal building. Illegal buildings are not protected by law. If it is recognized as an illegal building, there will be greater risks in the face of demolition. If you want compensation and resettlement, it depends on your negotiation with the demolition implementation unit.
Second: Shanghai's current demolition policy adopts the method of "counting bricks" and "counting heads", which means that it depends on both the area and the registered residence. Therefore, even if your house is not approved for the right to use the homestead in the end, although the legal area is only over 80 square meters, because there are 3 accounts and 8 people in the house, the compensation for demolition will not be calculated only according to the standard of 80 square meters. Of course, if conditions permit, I suggest that you reissue the homestead use right certificate.