The introduction of EU directives 2002/91/EC and 2003/87/EC both prompt a reduction in energy consumption from European buildings. Buildings account for 50% of European energy use. Traditional prescriptive based approaches to building energy performance have not yielded desired energy savings. In addition, energy consumption is seldom compared with design intent. A whole building life cycle performance based approach is ultimately required. This talk introduces and demonstrates Environmental Effectiveness Ratios. These ratios are based upon data from sensors, a calibrated simulation model and a threshold simulation model. The ratios help identify areas of energy waste from whole building though to system or component level. Design professionals and building managers alike may reduce building life cycle energy consumption by analyzing these ratios in the software tool BuildingPI and acting accordingly.