If you are going to use the services of any trade person or company in France, especially builders, then you can quickly check their status and things like any judgments against them at the official Government website – it is in English and you can select, pay for and download a lot of information – most papers only cost a few euro and it could save you a lot of grief and expense.
You can even check on me to see my official working status, and registration details.
If anyone who offers services is not registered, then don’t use them, it is illegal for you to employ the services of anyone in France who is not correctly registered and you risk severe penalties by employing them.