Cost-effective energy savings potential of Italian residential building stock

摘要

Deep renovation of existing building stock is the key action inorder to significantly reduce building sector energy consumption.Furthermore, it cannot only contribute in reaching Europeanenergy targets but also in helping economic growth.This paper shows that cost-effective renovations could beimplemented in the 59 % of the Italian building stock. The correspondingpotential energy savings amounts to 8 Mtoe (i.e.26 % of households actual consumption) and overall investmentcosts would be €137 G. Incentives play a key role: if therate of tax credit will decrease, potential energy savings wouldreduce down to 3 Mtoe.The adopted methodology is founded on the creation of adatabase of the Italian residential building stock, linking thedata of the last household census with buildings “archetypes”,i.e. a set of 140 buildings representative of the Italian stock(classified according size, age and climate zone). This databaseis coupled with a tool able to evaluate energetically and economicallydifferent energy efficiency measures, including walland roof thermal insulation, double and triple glazing, shadingdevices, condensing boilers, thermostatic valves and thermalsolar collectors. Building energy performance is calculated viaa dynamic simulation, while the cost data are based both onnational price lists and recent construction projects. Then, usinga cost-optimal approach complying with Directive 2010/31and Delegated Regulation 244/2012, the best renovation packagesare selected for each building in order to quantify the costeffectivesavings potential of the building stock. Furthermore,the methodology includes a sensitivity analysis on the amountof incentives (tax credit covering a percentage of investment)as well as the possibility to impose constraints on investmentprofitability (payback period).