Ascó turns a building with apparently contradictory energy needs into an integrated thermal ecosystem. It simultaneously requires large amounts of heating and cooling, yet instead of treating these as separate demands, the project connects them through a geothermal energy hub. The most striking feature is the High Temperature Recovery system in-built in the heat pump: heat extracted from cooling the fitness areas can be reused for swimming-pool heating and DHW instead of being rejected outdoors. The project also recovers heat from humid swimming-pool air and from ventilation, while photovoltaic electricity can be converted into stored thermal energy in the building's water tanks. In other words, the building does not simply generate renewable energy; it continually recovers, reuses and stores energy that would otherwise be wasted. With a COP of 4.5, 133,208 kWh/year of estimated photovoltaic generation, 222,458 kWh/year of estimated total electricity savings and approximately 29.5 tonnes of CO₂ avoided annually, Ascó demonstrates how a complex public sports facility can combine comfort, resilience and energy efficiency in one integrated solution.