The relatively high installation costs for different types of shallow geothermal energy systems are obstacles that have lowered the impact of geothermal solutions in the renewable energy market. In order to reduce planning costs and obtain a lithological overview of geothermal potentials and drilling conditions, a pan-European geological overview map was created using freely accessible JRC (Joint Research Centre) data and ArcGIS software. JRC data were interpreted and merged together in order to collect information about the expenditure of installing geothermal systems in specific geological set-ups, and thereby select the most economic drilling technique. Within the four-year project of the European Union’s Horizon 2020 Research and Innovation Program, which is known as “Cheap-GSHPs” (the Cheap and efficient application of reliable Ground Source Heat exchangers and Pumps), the most diffused lithologies and corresponding drilling costs were analyzed to provide a 1 km × 1 km raster with the required underground information. The final outline map should be valid throughout Europe, and should respect the INSPIRE (INfrastructure for SPatial InfoRmation in Europe) guidelines.