This thesis examines the effects of electricity visualization in an office building. The subject was investigated through the creation of a web based visualization tool that was made accessible to the about 1500 employees in a large office building. The visualization was available for three weeks. During this period interviews, user studies and observations took place in order to evaluate what, if any, effects the visualization had on the attitudes and behaviors in the office. Electricity use data was collected and analyzed to see if the project had a statistically significant effect on the electricity consumption in the office. The results from the interviews and the data analysis indicate that no reduction in electricity consumption took place, and a number of factors that could increase the chances of success were identified. The workstations covered by an electricity meter should correspond to smaller organizational units in order to take advantage of existing group affiliations. Further, communication channels should be effective, so that as many workers as possible could be reached and become interested in the project. Finally, the goals of the project should be aligned with the goals of the workers to encourage behavioral change instead of making energy saving a burden that takes time from ordinary tasks. A slight change in attitude was detected, but this did not result in any change of behavior. One reason for the absence of change in behaviors was the feeling of lack of control over energy use.