A permis de construire is the most elaborate type of planning permission. You use it to build a house from scratch on a piece of land or to make substantial changes to your property such as adding on an extra floor or extension. It is also required when you demolish part of your property or create windows where there once was a blank wall.
The permis de construire takes time to apply for. It is compulsory to have an architect help you for new build or increases in habitable space* over 150m² as you will have to supply plans, 3D before and after images, and a lot of paperwork (such as water waste management plans etc). You can read more about what's involved in all stages,
here.
You’ll need to wait for at least 2 months for the Permis de Construire to be issued. Between the moment you apply for it and get your precious number, the application has to be approved by your local mairie and then by the local Prefecture. If the mairie request additional information within the first month, then the clock does not re-start until all the information is received. If you’re building near historical monuments, the “Architectes des Bâtiments de France” will have to give their opinion on it too – expect at least a month more, often two.
It is always better to find a good architect to help you out with a permis de construire. Preferably an architect who’s used to dealing with your local mairie. This will speed up the application process. Once you’ve received approval from the mairie, you will receive your file with a dedicated number.
Note you will have to wait an extra 2 months for due diligence, including giving neighbours time to object, before you can start working.
To find out more about a Permis de Construire, you can look up the information on the French government
website.
What is habitable space?
Habitable surface floor area (surface de plancher) of the property. In summary it is defined in French law as: the total enclosed and covered floor area of the building that has a minimum height of 1.80m, calculated from the interior walls of the building. It excludes garages.