The whole project started with the replacement of the central steam boiler rooms in both premises with new natural gas heat sources located directly in the heated buildings, new medium pressure gas distribution systems, modifications of heating systems, reconstruction of transformer stations, reconstruction of indoor and outdoor lighting, use of waste heat, insulation of some roofs and installation of water savers. Temperature, humidity, and CO2 sensors play an essential role, which, in addition to saving energy, also contribute to improving the indoor environment of the buildings. The selection of energy-saving measures was guided by the savings potential they would bring. As a result, the investment of CZK 71 million will be returned to VOP by the end of the project, i.e. by 2028 at the latest.