Buildings and equipment built in the Francisian flood zones prior to the approval of the PPRI were not designed to withstand flooding. Several thousand public buildings are in this situation today. Diagnostics of the vulnerability of these buildings and equipment help to meet different objectives: — Awareness of the issues and effects of floods — Fine knowledge of vulnerability at the building level — Preparation of vulnerability reduction work on sites and equipment — Preparation of organisational approaches to reduce vulnerability Vulnerability diagnostics are an important part of the process of acculturation and consideration of risk. The aim of the EPTB for this action is to encourage different public actors to implement vulnerability diagnoses. The expected results are to multiply the number of public actors who will take these steps.