• Developed new DT Strategy Schedule & Document to provide pragmatic development guidance • Developed a unified DT architecture to integrate sustainability assessments • Demonstrated through a case study of a university building • Created an immersive 3D visualization to enable actionable decision support This paper investigates the application of Digital Twin (DT) technology to support sustainability assessments in the built environment. While DTs are increasingly adopted in building contexts, three key fundamental challenges persist: (1) lack of pragmatic guidance for DT development, (2) limited integration of multiple sustainability assessments, and (3) insufficient support for decision-making through contextualized visualization. To address the scientific gaps, this study introduced the Digital Twin Strategy Schedule and Digital Twin Strategy Document, which provide guidance for defining DT objectives, analytical scope, and data requirements. These instruments were derived by interpreting and adapting general DT strategy guidelines to the specific needs of sustainability-oriented DTs for buildings and are iteratively refined through application to a real-world case study. The proposed framework integrated energy modeling, Material Flow Analysis, and Life Cycle Assessment within a unified architecture. An automated workflow was developed to link Building Information Modeling, the analytical models, and Building Automation System data, enabling consistent data exchange, validation, and traceability. The proposed approach was demonstrated through a case study of a university building equipped with smart sensors. Sustainability indicators and operational performance metrics were visualized within an immersive, interactive 3D environment, supporting anomaly detection and alert-based communication. Results highlighted the potential of DTs to enhance sustainability-informed decision-making and challenges associated with data completeness, semantic alignment, and geometric interoperability. Overall, this work formalizes and demonstrates a DT architecture to connect sustainability analytics with spatially contextualized visualization, moving beyond static dashboards toward actionable decision support for building operation and maintenance.
Geremicca et al. (Sun,) studied this question.