Energy  certification is mandatory for trade and service buildings, public buildings and others. Energy usage optimization plays a relevant role in your competitiveness and an important environmental gain. Through energy certification, we can characterize the installation and the main consuming equipment. We identify the opportunities to reduce the energy consumption by replacing equipment, and by changing processes. Refund, as specialist in investment and real estate management, requested DELAB’s support to renew the Energy Certificate of Leya Building, located in Alfragide, which has about 5 000 m2.