Rock mass heat transfer potential as the energy source of buildings with different energy performance in the northern part of Central Europe

The paper aims to identify the rock mass potential as the heating source for buildings with different energy performance, under climate conditions of the northern part of Central Europe. The analysis was performed as a study on three levels of building energy performance and ten different sites. The analysis of the Ground Heat Exchanger (GHE) was made on the basis of the specific average building's annual energy demands. The use of vertical heat exchangers was adopted. The total length of boreholes was determined by three methods: ASHRAE, Bose's, and a simplified analytical method. As a result of the investigation, it was found that the relationship between demand for heat power in the general building model and climate severity is linear, but its directionality factor depends on the energy quality of the building. The final energy demand for space heating is not concentrated according to climate zones. The cooling demand indicates a latitudinal course. The main impact on the number of boreholes of the assumed depth is the thermal quality of the rock. Finally, it was demonstrated that rock mass energy is a potential and promising energy source for buildings with different energy performance. This study provides a broader background by highlighting the increasing role of local renewable energy sources in building heating and cooling in the northern part of Central Europe. The aim is to assess the potential of rock mass energy for buildings with varying energy performance standards, considering geological variability and climate severity. Potential applications include supporting the design of energy systems for new and retrofitted office buildings, optimizing borehole heat exchanger length, and contributing to low-emission energy strategies in the region.