Decisions concerning energy retrofit of historical buildings should be based on a complex set of parameters, ranging from not-tangible to tangible values, such as the historical and the cultural value, the expected costs and benefits, the environmental impacts. The tangible values, such as the monetary costs and benefits, are often prioritized considering their measurability, however neglecting that they are frequently affected by important uncertainties (related e.g. to the evolution of the macro-economic scenario, to the building components maintenance and replacement needs, etc.). This fact can lead to improper design choices and consequently to the risk of losing part of the building tangible or not-tangible value. For this reason, it is necessary to improve decision-making processes and tools, also considering uncertainty and sensitivity analysis as part of the design process related to the energy retrofit of historical buildings. In this paper we show the impact of different assumptions regarding future possible macro-economic scenarios on the monetary benefits of a historic building renovation intervention. A “probabilistic” Life Cycle Costing tool, developed through the software environment for statistical computing “R”, has been used to evaluate the parameters mostly influencing the global costs of the typical energy retrofit measures applied to a building case-study. Results demonstrate how the uncertainties related to the economic parameters are the most influencing the output variance. The uncertainties related to the building periodic maintenance and the energy costs are also prevailing on those related to the initial investment costs
