While recent studies have shown an important gap between design and real energy use of multifamily buildings, this study analyses the energy performance gap for student housing. A very high energy performance (VHEP) student residency was analysed in detail, followed by a comparison of energy and water consumption with student residencies and other dwellings in Geneva. The analysis shows that for this VHEP residency the limit values according to the actual thermal regulations and MINERGIE label are exceeded: actual heat demand is 98 MJ/m2.a for heating (without double-flow ventilation) and 116 MJ/m2.a for hot water while the MINERGIE-index is 137 MJ/m2 (38 kWh/m2.a). Nevertheless, its thermal energy consumption (IDC=224 MJ/m2.a) is similar to other VHEP buildings, and half of Geneva's average values. The study points to factors which highly influence real performance of VHEP buildings and concludes that there is a huge optimisation potential during use phase of a building.