Are you about to sign a preliminary contract? This is known as a "pre-contract". The preliminary contract and the sales agreement are two contracts with different consequences for the buyer and the seller
Before the sale or rental, the law requires the establishment of a technical diagnostic file (DDT). Its objective: to inform and protect the buyer or the tenant.
You leave with the keys, but without your Ownership Title. However, the notaire has given you the Certificates of Ownership. These certificates represent, in some way, a provisional and simplified Ownership Title.
A building’s seller (apartment, house, land) is obliged to inform his buyer as soon as the preliminary contract has been signed. It is important to get advice before putting a property up for sale.