In the framework of the operation, the castle bridge and the castle Kamen are planned to be carried out on both the envelope and the energy systems of the buildings. The bridge Castle is located in the health complex of the Novo mesto General Hospital, and Kamen Castle is located on the edge of the health complex in Novo mesto. Due to the age of buildings and, above all, the debilitating and wasteful energy systems, the use of energy and consequently the cost of operating the facilities are increasing. In addition, it is also necessary to assess the state of the buildings from the point of view of ensuring adequate working conditions and the reliability of the systems that guarantee these conditions, the energy system is crucial. The buildings that are subject to energy renovation are in poor condition in terms of the state of the construction envelope and the state of mechanical and electrical installations. The analysis of the state of the facilities demonstrates the need for the implementation of a comprehensive energy renovation project mainly due to high costs of operation and maintenance of facilities, energy waste of buildings primarily due to inadequate heat