To this end, the centre has decided to undertake surveys of the monuments in its charge. The purpose of these expert analyses, which have historical, technical and scientific components, is to assess the state of conservation of roof structures and façades, the solidity of the structures and the regulatory compliance of electrical facilities and of systems to protect against fire and intruders.

This review of their general state of repair will provide the basis for scheduling maintenance, repair and restoration works on each monument over the course of several years. It should also result in more effective prevention of accidents, such as the collapse of the ceiling of the Château de Champs-sur-Marne in September 2006 and the fire at the Royal Lodge of Angers in January 2009.

In order to limit the number of substantial and costly restoration operations, the CMN is also implementing an ongoing schedule of repair works.

The purpose of these works is to limit deterioration in the general state of repair of the buildings as well as to pre-empt damage, which can sometimes prove to be serious. They are undertaken by Public Works Project Managers, who are urban state architects working for the CMN and who are also the curators of national monuments. They know these monuments inside out and are well-placed to identify and implement the measures necessary for the effective conservation of the edifices: the repair of surface coatings and of sections of roofing, the replacement of door-frames or window-frames and of flooring, the reinforcement of retaining walls and so on.