French planning rules are set out in the “Code de l'Urbanisme".
 
 
The most important type of certificate is the “Certificat d'Urbanisme” (CDU), which states the right, or not, to build on specific land and gives details about the taxation of the land and buildings. There are two kinds of certificat d'urbanisme: certificat de simple information (certificate of information), information on the existing rights of the property and certificat opérationnel (operational certificate), which shows you whether or not a specific development can be undertaken.
 
Once your house has been built, or if you buy an existing property, the need for further planning consents depends on the type of renovation.
 
Failure to obtain planning permission where it is needed can result in the demolition of renovation work, even of the whole building and a financial penalty.