Digital Twin Service for Energy Efficiency in Heritage Buildings: The HERIT4AGES Project Technological Framework

The conservation of built cultural heritage demands a careful balance between safeguarding cultural values and meeting contemporary performance requirements. In this context, digital twins represent promising decision-support tools for energy management, though their deployment remains challenging due to heterogeneous HBIM practices, poor interoperability with simulation environments, limited monitoring systems, and the persistent "performance gap" between simulated and measured data. This paper presents a DT service developed within the HERIT4AGES project, which promotes energy renovation solutions for built heritage based on recycled materials and non-intrusive smart technologies. The proposed approach relies on a modular microservice that integrates structured HBIM data, operational data from sensors, and dynamic performance simulations, enabling calibration and iterative alignment of simulation inputs for scenario-based assessments. The methodology is being deployed across five pilot sites in four European countries, with this study focusing on the Italian demonstrator. The workflow moves through HBIM generation, sensor monitoring deployment, HBIM-to-BEM conversion, energy simulation and calibration, and final integration into a user-friendly interface. The service tracks key KPIs such as energy use, indoor thermal comfort, and condensation risk, supporting informed comparisons of retrofitting strategies. Future developments will extend the ecosystem to enable integrated analysis of energy, accessibility, environmental, and maintenance aspects.