Answer: the architect is useful if your project is subject to a building permit.
It is necessary to call on an architect for any project, whether it is a construction or an extension, subject to the request for a building permit. What the architect brings you is above all a competence recognized by law. If you work with an architect, you ensure the legality and sustainability of your work. If you have any doubts about your construction project, you can approach the architectural, town planning and environment council of your department. Here you will find experts who can provide you with free information. Concerning natural persons who build or wish to rehabilitate for themselves, the involvement of an architect is optional but recommended if the construction area does not exceed 170 m².