This paper describes a new method to measure activity in buildings, using WiFi connections as a proxy for human occupancy. The number of WiFi connections and energy consumption (electricity, steam and chilled water) were compared for two buildings of the Massachusetts Institute of Technology’s campus. Results demonstrate that while electricity consumption corresponds to occupancy fairly well, the operation of HVAC systems in the buildings follows more the external temperature than the occupancy. The paper identifies
future steps that could improve energy usage, such as a use of the space within buildings that could be planned to save energy.