The opening of a building means that a "sales license" has been obtained during the construction of the building and it can legally promote pre-sales to the outside world. It is a grand event held to officially launch the market, just like the opening of a hotel. Same.
In layman’s terms, it’s time to start selling your house. If you are buying an off-plan house (that is, the building is under construction), you can generally only handle the purchase contract, bank loan, deed tax, etc. when the house is opened, and you cannot move into the house immediately. If you are purchasing an existing house, generally after completing the same procedures as above, you can receive the key and move in after the decoration is completed.
Extended information:
Necessary conditions for the opening of the building: all five certificates must be present.
That is, obtain according to law:
1. "State-owned Land Use Certificate"
2. "Construction Land Planning Permit"
3. "Construction Project Planning Permit" 》
4. "Construction Project Construction License"
5. "Commodity Housing Pre-Sale License"
Reference: Opening (real estate market terminology) - Baidu Encyclopedia