The data presented here has been published as part of the iDesignRES project under Work Package 1(WP1), specifically for Task 1.1 and Task 1.3. These tasks focused on data collection and comprehensiveGIS-based modelling to generate high-resolution spatial data on heat demand, district heatingpotentials across Europe, and waste heat sources with their corresponding potential.The dataset includes aggregated estimates at the NUTS2 level for heat demand in residential andservice buildings; district heating potential—covering residential, service, and industrial sectors—alongwith associated investment costs based on a 55% market share; and the potential of waste heat,disaggregated by source and temperature level. The data spans all EU27 countries as well as the UnitedKingdom (UK). The 55% market share refers on an accumulated share across EU27, but varies amongthe countries, depending on where the potentials are high.