Building envelope resilience to climate change under Italian energy policies

As a result of recent geopolitical events, zero-energy buildings must include a climate change prevention strategy. Policies are moving in the direction of an energy transition. Italian regulations, complying with European directives, are driving toward increasingly thermally insulated buildings. An important objective of this study is to determine whether updates to building energy efficiency regulations from 2005, particularly for the envelope, will result in increased envelope resilience to climate change. The building was analyzed without air conditioning, simulating an extreme case of a long period without gas supply. It has been located in all Italian climate zones and adapted to respect the local requirements imposed by national regulations for each climate zone. The legal requirements investigated are Italian Legislative Decree 192/2005, Italian Ministerial Decree 26/6/2015, and Italian Ministerial Decree 6/8/2020. The forecasting analyses were carried out considering the years 2030, 2050, and 2070 and three Representative Concentration Pathway scenarios (RCP 2.6, 4.5, and 8.5). The analysis of the results focused on trends of heating, cooling and total thermal performance index from the years 2030–2070. For all RCP scenarios, the 2015 and 2020 requirements optimize total envelope performance in terms of total thermal performance index and perform particularly well with the 2020 limits. It is clean that lowering the transmittance of the envelope components leads to an improvement in the total thermal performance index which, however, by maintaining the same trend over the years with the different scenarios, suggests that the resilience of the envelope to climate change is actually little affected by the transmittance value of the component structures.