When buildings are built, they are typically designed for a specific use and occupancy. This tends to change over the years. Building systems should be commissioned as construction is completed to verify that they operate as designed, but often the commissioning process is neglected. A National Energy Management Institute study estimates less than 5% of existing buildings have been commissioned. Buildings that have changing uses and those that haven’t been commissioned after construction can be secretly wasting energy. In both cases, retrocommissioning can help