The calculation of the energy demand [kWh/m2 year] for a residential bulding under italian law

In this paper the authors present the first results of a research conducted on reducing energy consumption in residential buildings in accordance with Italian law. In particular, the authors have described an algorithm for rapid calculation of energy consumption in residential buildings within the limits of the energy performance index, EPiL, set by Italian legislation currently in force. The algorithm, as a function of degree-days in the location and of the report form (S/V)of the building, is used to determine the energy consumption classes in (the case of) a building with reduction of consumption to make the building less energy-consuming by switching to energy classes A +, A and B instead of energy class C. The authors, in the first part of the research paper, recall the main rules in force in Italy that regulate: • The reduction of energy consumption for winter heating of residences; • The reduction of energy consumption for the production of domestic hot water; In the second part, however, they demonstrate how the relationship has been obtained by calculation that allows you to evaluate the energy performance index limit for heating in winter, depending on the aspect of the surface area to volume (S/V) ratio of the building, object of study, and degree days of the locality where the building is located.