Economics-Based Comparison of Retrofitting Interventions for Existing Industrial Buildings Through Life Cycle Cost Analysis

Nowadays, the building sector is responsible for 30% of the global final energy demand and 37% of global energy and process emissions. In this context, industrial buildings account for 33% of global final energy consumption, representing one of the most energy-intensive sectors. The challenging European goal of achieving a carbon-free economy by 2050 is not reachable without intervening on the existing building stock. This research study aims to propose several retrofitting measures implemented in existing Italian industrial facilities to ameliorate energy and environmental performance, as well as to guarantee better indoor thermal conditions for workers. These interventions deal with both external envelope interventions and conditioning system improvements, along with their possible combination, to identify the most cost-effective solutions. A life cycle cost (LCC) analysis is performed to assess and compare the different redevelopment measures to identify the advisable ones considering the initial investment expenditure and operational and maintenance costs during a life span of 20 years. To define the cost-effective solution, different synthetic indexes are considered in the analysis. A sensitivity analysis is conducted on the discount rate and the operational life of the building (20 years). Redevelopment measures concerning conditioning systems seem to be the most advantageous ones in terms of operational energy savings and payback period evaluation if renewables are installed. The latter possibly makes industrial buildings carbon-neutral. The interventions on the external envelope allow buildings to meet the current Italian regulations in terms of thermodynamic properties, even if they affect the operational cost to a lesser extent.