Cost-effective energy savings potential of Italian residential building stock

摘要

Deep renovation of existing building stock is the key action in order to significantly reduce building sector energy consumption. Furthermore, it cannot only contribute in reaching European energy targets but also in helping economic growth. This paper shows that cost-effective renovations could be implemented in the 59 % of the Italian building stock. The corresponding potential energy savings amounts to 8 Mtoe (i.e. 26 % of households actual consumption) and overall investment costs would be ?137 G. Incentives play a key role: if the rate of tax credit will decrease, potential energy savings would reduce down to 3 Mtoe. The adopted methodology is founded on the creation of a database of the Italian residential building stock, linking the data 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 database is coupled with a tool able to evaluate energetically and economically different energy efficiency measures, including wall and roof thermal insulation, double and triple glazing, shading devices, condensing boilers, thermostatic valves and thermal solar collectors. Building energy performance is calculated via a dynamic simulation, while the cost data are based both on national price lists and recent construction projects. Then, using a cost-optimal approach complying with Directive 2010/31 and Delegated Regulation 244/2012, the best renovation packages are selected for each building in order to quantify the costeffective savings potential of the building stock. Furthermore, the methodology includes a sensitivity analysis on the amount of incentives (tax credit covering a percentage of investment) as well as the possibility to impose constraints on investment profitability (payback period).