The purpose of this research is to illustrate, through a case study, a multilevel decision-making process able to support the decision maker in optimizing investment choices for the efficient allocation of public resources, with specific reference to recovery and adaptation to the reuse of unused historical public heritage. During the evaluation process, two methods in particular were combined according to a multiphase design: (i) a multi-criteria analysis to identify the highest and best use among alternative reuse scenarios and (ii) a discounted cash flow analysis to support verification of the financial feasibility of the investment, in the hypothesis of an enhancement concession in a public–private partnership. Each method was applied in parallel to the evolution of the different design scenarios. The results of the study show that hybrid approaches are a promising line of research in the field of evaluation and urban design, applied to cultural heritage.