For any project to renovate or construct a building over 170sq m Surface Hors Oeuvre Net (SHON), net habitable space, the law states that an application for a Permis de Construire cannot be investigated unless an architect registered under Architectes des Bâtiment du France has "established the architectural project". This means that the architect has to draw up plans and make the planning application on your behalf.
 
 

Calculating the relevant SHON must include all habitable areas and measurements must include the thickness of the walls, which must therefore be measured to the outside face. The calculation normally excludes open areas at ground level such as a porch, balconies, basements, garages and any habitable area where the headroom is less than 1.8m, such as rooms under the eaves.
 
 

Each French département's Direction Départementale de l'Equipment (DDE) has a consulting architect (architecte conseil) who will provide free advice on the type of building permit required, and confirm if a project constitutes more than 170sq m net habitable space and therefore require the services of an architect. This service is free of charge, available by appointment.
 
 

The technical dossier which the architect has to produce must contain a written submission explaining the visual impact of the project, as well as site plans (scale 1:5000 or 1:10000 for the land and scale 1:500 for the property), floor, section and elevation plans (scale 1:100), photographs of the existing site and an elevation of the proposed improvements.