Building EQ aimed at strengthening the implementation of the EPBD by linking the certification process with commissioning and optimization of building performance. Within the scope of the project methodologies and tools were developed that could be used for ongoing commissioning and optimization of non-domestic buildings using gathered data from the certification process according to the EPBD. The emphasis was on feasibility and cost-effectiveness with regard to building-practice. Today, after the certification, usually there is no continuous evaluation of the building performance in order to reach or maintain an energy-efficient operation. As a result the performance of buildings is often poor and does not represent the energetic / economic optimum. The consortium evaluated the developed methods and tools in 11 demonstration buildings in the 4 participating countries. Main target groups were the industry for Facility and Energy Management, real estate owners, energy agencies and energy consultants.