An European study on the effect of coupling electric generation by means of photovoltaic with GSHP in a building retrofit in an urban area The objective of this project has been to study the possibility of coupling photovoltaic systems with Ground Source Heat Pumps in buildings that are located within urban centres, in order to satisfy their energy demand. Throughout the analysis, a distinction has been made between Existing and Historical buildings and the study archetype has been the single-family Terraced House. To expand the study and make it more realistic, the electrical load of buildings has also been considered. Electrical load corresponds to the electrical energy used in a home for electronic devices and lighting. The study has been carried out in three European cities, each chosen as representative of a certain type of climate. The selected cities have been Athens (warm climate), Strasbourg (temperate climate) and Helsinki (cold climate). In each of these places, solar radiation and cost of living are very different, greatly influencing the study. TRNSYS program has been used to perform simulations and find out the power values that the photovoltaic installation generates every hour and in every climate. These simulations have been made considering various orientations of the solar panels, in order to obtain data for different positioning of the buildings. A total of 150 alternatives have been studied for each climate, including different modifications of the building's systems and facilities. The possibility of modifying only the generator, incorporating the photovoltaic system with or without a battery, changing the terminal units and even improving the building envelope to improve insulation and reduce thermal load has been investigated. An energy and an economic analysis have been carried out to better describe the suggested solutions.