Clusterised calculation for digital thermal modelling of heritage — energy optimisation. At a time of mass awareness of the impacts of climate change linked mainly to increasing carbon emissions, reducing and controlling energy consumption are major challenges for the future. Meeting this challenge will help contain climate change. This project will accelerate the identification of energy saving deposits in existing heritage using clusterised calculation and to be tested virtually before undertaking improvement work, the efficiency of the technical solutions proposed by architects and engineers. This project will make it possible to secure the expected results against the theoretical calculations corrected by the integration into equations of the physical sensors in place in buildings and will also allow to estimate, with near absolute reliability, the impact of the decrease in the carbon footprint linked to the proposals of the resulting amending work.