Economic feasibility and energy retrofit: a decision-making tool for large property assets

The paper aims to deepen the collaboration between feasibility analysis and energy efficiency measures in built heritage, to support the stakeholders during their decision-making process. Whether applied to historic or traditional assets, energy efficiency is a complex and expensive operation, especially if broaden to large building stocks: it becomes crucial to evaluate alternative scenarios and identify the actions that can lead to the optimal resources allocation, considering the best balance between energy savings and total costs. The assessment at the early stage of economic convenience is strategic, including methods capable of controlling both the energetic behavior of the buildings and the monetary amounts involved, such as the life cycle costing, the discounted payback period, the discounted cash flow analysis or others. This study, hence, intends to elaborate a replicable model for the preventive economic evaluation in retrofit operations, especially for large property portfolios, where it is harder to define which combination of interventions leads to the optimal result. In particular, this model is processed starting from the project, " Unife sostenibile: screening energetico del patrimonio edilizio dell’ateneo di Ferrara e proposte preliminari per la fase di programmazione degli interventi di retrofit", developed by the Research Center “Achitettura> Energia (Unife).” The project chosen has analyzed a group of about 50 buildings in Ferrara, finding their thermo-hygrometric behavior, their annual consumption and other information about their installation systems, giving us a significant database necessary to implement the economic evaluation model. Thus, the goal of the research is to produce a calculation tool which can be easily used, and which can quickly identify the best retrofit scenario. Moreover, the model should be exportable and applicable in other contexts as well by varying the input data only.