Coupe (section or cross section) is used contrary to élévation (elevation).
A coup emphasises on what is shown when one cuts through an object or a building.
A plan could be defined as a section in the horizontal plane; sections are normally cross or longitudinal sections.
In the picture a longitudinal section of the Saint-Bonnet in Saint-Bonnet-de-Cray.
|Saint-Bonnet - Saint-Bonnet-de-Cray|