If you intend to undertake a building or remodeling project, making sure that there are no zoning or other restrictions interfering with your plans should be undertaken before you buy the property. Your absolute first step should be to retrieve a document called plan local d'urbanisme from the mayor's office. You will also want to obtain both le certificat d'urbanisme ordinaire and le certificat pré-opérationnel. All three documents will help provide information about whether you can do what you intend with your property. It is also a good idea to contact the Direction départementale de l'équipement and get the schémas d'urbanisme to make sure that there are no highly undesirable projects planned in the vicinity.
Some cities do not have a plan local d'urbanisme , but this does not mean that you can do whatever you want with your property. In this case, you need to follow the règles générales du règlement national d'urbanisme. Any restrictions on what you can do with your property will vary greatly from one type of housing to another and from one municipality to another. In general, the older the property, the more stringent and numerous the restrictions are likely to be. You should make sure to check out the rules and regulations of your lotissement or apartment building, if you are planning to buy this type of property, to make sure that none of the owners' association rules would interfere with your plans. Likewise, your project should be in compliance with the laws that seek to protect mountainous and waterfront areas, historic, and other protected sites.
One of the difficulties in making sense of all these rules is that they do not originate from the same source. While some people have been successful at obtaining the zoning changes necessary to accommodate their project, this is rare, and you should not count on it. Keep in mind that France is a very centralized and bureaucratic society. The rules are numerous, complex, and monitored by people who are unwilling or unable to bend them.
I do not mean to scare you, but...
DON'T EVER ASSUME ANYTHING. Check it out instead!
Next, verify the size of the land you are about to buy, by hiring a surveyor. Though this information may be in a document called le cadastre, it is informational only and would not hold in a court of law. It would be prudent to independently determine the property's superficie.
French law gives the municipality the right of first refusal. All forthcoming purchases are routinely reported to the mayor's office. Before the purchase is final, the municipality can decide it is in the community's best interest to own the property, preempt the sale, and buy the property.
I present a cautionary tale on this topic. IT AIN'T OVER TILL IT'S OVER, to quote an American bard, Yogi Berra. A friend, let's call her Eleanor Weston (because she made me promise I'd use her real name) made a ridiculously low offer on a restaurant on the market for a decade. Her intention was to remodel the space into an apartment. To her surprise, and, to tell the truth, horror, her offer was accepted. There followed the usual choreography of visits and calls to the notaire and realtor. The compromis de vente was signed, the deposit made, and all that remained was her final signature. This was to happen on December 13. However, on December 8 the mayor and city council met, and ultimately blocked the sale. They wanted the village to purchase the building so that it would remain a restaurant. Thus, Eleanor was back to pounding the pavement (or stones) in search of a new domicile.
This is rarely invoked-but it happened to Eleanor. Don't incur expenses before the sale is final.