Abstract A system for capturing thermal energy is planned for installation at the ENEA-Casaccia centre (Italy). Costs, primary energy requirements, pollutant emissions and seasonal electricity consumption were estimated. The configuration based on four boreholes of different depths and the sizing of the vertical loop (double-U) were performed according to the ASHRAE method. This pilot plant, the first under construction within an Italian research centre, is part of a long-term research project funded by the Italian Ministry of Economic Development. The results of this research could be applied throughout the Italian Tyrrhenian Apennine margin, which is geologically characterised by highly conductive lithotypes.