ABSTRACT
The European Union (EU) has great targets for the reduction of energy consumption. Therefore, the Energy Performance of Buildings Directive introduced, in article 9, the “nearly ZeroEnergy Buildings” concept as a future requirement for all new buildings. The buildings constructions sector is continuously increasing and it is desired that by 2021 all new buildings to accomplish the “nearly Zero-Energy Building” standard. The greatest relevance for the energy consumption in the buildings sector stays in the existing buildings and especially in the old buildings that have a unique architectural character. Such buildings are difficult to rehabilitate because their architectural shape must remain intact. Authorities must agree the thermal rehabilitation of these types of buildings in order to avoid architectural modifications that may appear in the rehabilitation process. Therefore, engineers and architects must adopt such solutions that will not affect the historical and architectural qualities of the building.
