A simplified tool for the energy certification of Italian existing dwellings. Comparativeand sensitivity analyses

The article 6 clause 9 of the Italian Decree Law 192/05, that transposes the European Directive 2002/91/EC on the energy performance of buildings (EPBD), supportsthe definition of simplified methods in order to carry out the energy certification of existing buildings minimizing costs imposed on final users. In this contextITC-CNR (Construction Technologies Institute of the Italian National Research Council) and ENEA (Italian National Agency for New Technologies, Energyand Environment), developed DOCET, a tool which implements the procedures defined in the technicalstandards complying with and supporting the EPBD requirements. The tool aimed at the definition of algorithms able to establish relationships between qualitative and pre-processed information and quantitativecharacteristics of materials, building envelope components and technological plants, in order to reduce the number of information to be inputted by the user. One of the requirements set for the tool is to be conservativeand with a sufficiently accurate calculation engine respect to design and dynamic simulation tools.A detailed analysis was carried out in order to compare the energy performances of existing buildings, using different tools, based on different: calculation procedures,accuracy of input data and building physics. A sensitivity analysis was carried out in order to assess the influence of the single variables on the total energy performance of residential buildings.