The proposal of a new hybrid methodology for the impact assessment of energy efficiency interventions. An exploratory study

The paper proposes a preliminary analysis of a combination of two very interesting techniques used for assessing the economic and environmental sustainability of retrofitting interventions in the building sector and their eco-efficiency. Indeed, one of the most popular methodologies proposed by the literature is the Life Cycle Assessment (i.e., LCA) because it considers not only costs and investment necessary for an intervention but also its spillovers on environment and society. For this reason, the LCA can be considered a technique able to guarantee a holistic assessment of retrofitting. However, data required for LCA are not always so easy to find and the necessity to evaluate the holistic impact of the intervention remains unsolved. This paper suggests a hybrid methodology for evaluating different solutions of retrofitting interventions combining results from Life Cycle Costing (LCC) with those from the non-parametric technique of the Directional Distance Function (DDF). The simplicity but, at the same time, the completeness of these methodologies allow to obtain efficient scores that can help to evaluate the holistic impact of retrofitting interventions on buildings, in particular in terms of energy savings and less CO2 emissions in the environment.