A Decision Making Tool for a Comprehensive Evaluation of Building Retrofitting Actions at the Regional Scale

Buildings in Europe account for 40% of total primary energy consumption and 36% of CO2 emissions. Nearly one-half of the building stock was built before modern energy efficiency standards and need urgent renovation. Urban retrofitting has emerged as a crucial factor for bringing about a radical change, the new construction rate being lower than 1%. Nevertheless, an accepted and consolidated methodology for refurbishing the existing housing stock is still lacking. The study presents an operating methodology for the optimization of the retrofitting process, based on energy efficiency and cost-effectiveness, as well as users' comfort, in the building asset of ITEA SpA, the social housing institute for the Province of Trento (Italy), which manages more than 600 buildings. The research consists of the following stages: (1) definition of building classes, similar in age, dimension, typology, construction system and location; (2) analysis of plant systems and recognition of cases significant for classifying buildings in term of energy class; (3) identification of possible improvements and related cost-benefits; and (4) extension of the results to the whole building class. A tool is here proposed, intended for use by ITEA in order to set medium-and long-term plans. The tool does not consider only the effective sustainability of the controlling body intervention but also the final users' full satisfaction.