The presented tool was applied to a supermarket building with a total surface area of 140 m2 in Thessalonica, Greece. The energy demand of the building is fully covered by natural gas for the operation of HVAC system, computers, lights, etc. Especially, four A/C units are used to cover the needs of heating and cooling in the building. The operation of building automation system, including the installation of master generator, energy analyser count and temperature sensors, with the combination of the proposed tool is estimated to begin in June 2011. Currently, first test beds are elaborated in order to ensure the proper operation of the tool.