Digitalization offers new, unprecedented possibilities to increase the energy efficiencyand improve the indoor conditions in buildings in a cost-efficient way. Smart buildings are seen bymany stakeholders as the way forward. Smart buildings feature advanced monitoring and controlsystems that allow a better control of the buildings’ indoor spaces, but it is becoming evident that themassive amount of data produced in smart buildings is rarely used. This work presents a long-termevaluation of a smart building testbed for one year; the building features state-of-the-art monitoringcapability and local energy generation (PV). The analysis shows room for improving energy efficiencyand indoor comfort due to non-optimal control settings; for instance, average indoor temperaturesin all winter months were above 24 ◦C. The analysis of electricity and domestic hot water use hasshown a relevant spread in average use, with single users consuming approximately four times morethan the average users. The combination of CO2 and temperature sensor was sufficient to pinpointthe anomalous operation of windows in wintertime, which has an impact on energy use for spaceheating. Although the quantification of the impact of users on the overall energy performance ofthe building was beyond the scope of this paper, this study showcases that modern commercialmonitoring systems for buildings have the potential to identify anomalies. The evidence collectedin the paper suggests that this data could be used to promote energy-efficient behaviors amongbuilding occupants and shows that cost-effective actions could be carried out if data generated by themonitoring and control systems were used more extensively.