Impact of Climate and Economic Scenarios on the Global Costs of Nearly Zero Energy Buildings Renovations. A Stochastic LCC on a Reference Multi-story Building

National long-term building renovation strategies should reduce the actual financial gap between nearly Zero Energy (nZE) and “minimum energy requirement” levels, to enlarge the impact of buildings’ energy saving on climate neutrality. However, the design of specific policies to bridge this gap strongly depends on the long-term expected value and volatility of the macroeconomic environment during the building's lifetime. Standardized Life Cycle Costing methods disregard the long-term uncertainty affecting the macroeconomic variables and consequently misrepresent the associated risk on the economic convenience of building renovation. The present work applies a “stochastic” approach to LCC on alternative renovation options of a reference building located in different Italian climate areas towards the nZE target. The analysis focuses on the analysis of the impact of alternative macroeconomic scenarios on the investment gap between the “cost-optimal” and the nZE solutions. A widespread application of this methodology in the context of the European “Cost-Optimal” framework would allow establishing specific funding schemes and financing instruments to push a real “renovation wave” of EU buildings.