the certification scheme energy smart is used to rate and certify the energy performance of commercial buildings it was originally developed by the energy sustainability unit esu at the national university of singapore and the national environment agency of singapore to target offices hotels and shopping malls the scheme is voluntary and most commercial enterprises participate because it can be used as part of their branding strategies the european council for an energy efficient economy has established that it is advice on energy efficiency improvements rather than solely ratings and certifications that primarily mobilize markets to achieve energy savings measures