A project began as a post occupancy evaluation of lighting controls installed in a range of buildings. Actual controlled lighting consumption was to be compared against past billing or simulated energy consumption. However, when the research began it was found that the controls had been removed from two out of the three buildings. This raised a much bigger research question as to why were the controls disconnected and what were the factors governing success or failure of these systems? A whole new methodology from that first envisaged had to be established. To find out what people know, or think, it is necessary to ask them. A framework was created to determine if there was correlation between past findings and the reasons for failure in the case studies. The research that followed posed many difficult challenges including the use of qualitative data in an engineering environment. Some of the findings included: . Comparatively high maintenance costs . Misinterpretations of commissioning processes . Incomplete analysis prior to installation . The requirement for post occupancy evaluation in current engineering practices