Because of the scale and the technical specialisation required, restoration work must be preceded by a survey to assess the condition of the property, be it a monument or a piece of furniture, and a decision made on the type of restoration demanded. At the château of Azay-le Rideau, for example, an extensive series of works is underway to restore the roof coverings, the exterior joinery and the façades of the monument.
In addition to carrying out restoration projects, the Centre des monuments nationaux is also responsible for improving the overall condition of the assets within its remit.
To this end, the CMN carries out studies to assess the monuments and collections under its charge. The historic, technical and scientific surveys provide evaluations on the state of conservation of objects, roofs, façades and structures, but also on the compliance of electric installations and fire safety and security systems.
The building health check serves as the foundation for developing a programme for the maintenance, repair and restoration of monuments and collections over several years.
To reduce the prohibitive and onerous cost of restoration operations, the CMN also carries out repairs. This work is aimed at preventing the deterioration of buildings and collections. Repairs on monuments are done under the oversight of the CMN's State architects and town planners, as well as heritage officers for national monuments. These experts know the monuments inside out and are therefore able to determine and implement the measures needed for a building's preservation, whether it be mending rendering or roofing, replacing door frames or floorboards or strengthening retaining walls.