Advances in building energy efficiency are often technology focussed and their efficacy can be limited due to the behaviour and activity of building occupants. Consequently, there is a need to have a more detailed understanding of building-occupant interaction, especially in multi-use spaces where this is less consistent. This research included intensive monitoring of a case study venue building located on a university campus in the UK in order to analyse its energy performance and identify energy savings opportunities. Results are presented from three diverse uses of the building; a graduation ceremony, a ball, and a concert, with each analysed as a separate case study. Each of these events had different requirements of the space, e.g. in terms of lighting, small power use, and occupancy, consequently placing different demands on building services. For each of the three case studies, the monitoring programme covered standard measures of building performance such as energy consumption and internal conditions; including lux level, relative humidity, and temperature. Additionally, other factors that impact energy use such as event type, internal heat gains, and occupancy profile hours were monitored. Peak electricity demand between these three events varied by as much as 283%, and initial analysis indicates that this is mostly the result of lighting use which additionally contributed to internal heat gains. However, evidence from both environmental sensors and observations of building occupants indicated that occupant activity can have the greatest influence on internal heat gains. This has, specifically in the case of the graduation ceremony, led to the building exceeding its set point temperature, something that could potentially have been avoided had the heating been scheduled more appropriately to the building’s proposed use. Through exploring the relationships between the variables for each event, it has been possible to identify multiple energy savings opportunities unique to each event type. This paper suggests a method of building analysis that is relevant to both designers considering the flexibility of building use in their assumptions on energy use, and also to aid facilities managers in identifying the key factors to concentrate efforts on when carrying out proactive energy management of their buildings.