The POSTFIRE project addresses the vulnerability and resilience of urban systems, with the main objective of facilitating the recovery of cultural heritage buildings after fires. The project will investigate the behaviour of historic stone masonry after high temperature exposure at the material and structural scale, accounting for the effect of water quenching. The project will investigate the relations between microscopic phenomena and property changes; it will create a property database for the selected materials in post-fire conditions, and material models of immediate applicability in analytical and computer-based methods for structural performance assessment and calculation. The reliability of the database and models will be tested at the structural scale. Finally, the project will propose post-fire assessment guidelines for heritage buildings of France, to extend the benefits of the project among academy, professionals, and national and international normalisation committees.