Appropriate use of information and communications technology has the potential to greatly aid attempts to encourage energy efficient behavior in buildings. In this work, we investigate a system that combines detailed monitoring of energy use within domestic properties together with monitoring of the occupants use of space within those properties. This data allows for the generation of personalized energy feedback that is disaggregated to both individual appliances and individual people. It is hypothesized that such feedback could prove to have a greater and more durable impact than typical aggregated energy usage data. We develop a technology platform that combines wireless energy monitoring and occupancy monitoring that utilizes widely available Wi-Fi technology. This platform was deployed in an occupied domestic property that forms part of the Creative Energy Homes project at the University of Nottingham in the UK. A series of 2 case studies were performed with a single tenant to assess energy behavior before and after the delivery of disaggregated energy feedback. It was discovered that this data was at odds with the tenant’s perception of energy use thus supporting the need for such a level of detail. However, the availability of this data was shown to have both positive and negative consequences.