Recovery of CO2 emissions in energetic refurbishment for housing buildings

Energetic refurbishment allows reducing CO2 emissions production during the building use. It has a direct influence in the reduction of climate change impact, according to the objective of the European Union to reduce CO2 emissions 20% by 2020. But these refurbishments also generate emissions in the construction process. The present document aims to analyze CO2 emissions in the use stage of different building models and the improvement developed in several refurbishment works, estimate the CO2 emissions produced in these works, compare them, , and establish the time needed for this recovery. The study analyzes four different housing building models and applies twelve refurbishment works for the improvement of thermal isolation in the building covering and the heating system, and the sanitary hot water production. These processes are analyzed with the software CE3 for Spanish energy rating, and some of them with EDILCLIMA implemented in Italy. They are compared for the same latitude and similar climate conditions. CO2 emissions produced in these works are also studied from the BEDEC Bank database, developed by the Technological Institute for Construction in Catalonia. The results obtained show the differences between each refurbishment and the resulting benefit in CO2 emissions reduction. The energy consumed in the heating system has a large influence in the results. Besides, differences between refurbishment works in the covering thermal isolation are noticed. The comparison of the results in two countries shows differences in their realities and the solutions to implement in each situation. This study helps to establish priorities in different energy refurbishment works and suggest the possibility to use this methodology for identifying the best solution in energetic refurbishment for each building model.