In Europe, there is a clear long-term objective to decarbonize the energy system, but it is very unclear how this will be achieved in the heating and cooling sector. As a result, there is currently a lot of uncertainty among policymakers and investors in the heating and cooling sector, primarily due to a lack of knowledge about the long-term changes that will occur in the coming decades. This HRE proposal will enable new policies as well as prepare the ground for new investments by creating more certainty in relation to the changes that are required. The work in this proposal will build on three previous HRE studies, all of which have been successfully completed on time and all of which have already influenced high-level policymakers at EU and national level in Europe. The work from these previous studies will be significantly improved in this project