Bridging Real and Virtual Environments: A BIM-to-Game-Engine Digital Twin Framework for Real-Time IoT Air-Quality Monitoring of the Abercrombie Building

Digital twins are increasingly proposed as a means of bridging the physical and virtual representations of the built environment, yet many existing implementations remain static geometric replicas, or are confined to two-dimensional dashboards that offer limited immersion and do not preserve the semantic richness of the underlying Building Information Model (BIM). This paper presents the development and proof-of-concept evaluation of a real-time, Industry Foundation Classes (IFC)-based digital twin of the Abercrombie Building at Oxford Brookes University, developed by the Oxford Institute for Sustainable Development (OISD). IFC data derived from a two-dimensional Revit model of the building were imported into Unreal Engine, preserving the semantic hierarchy of individual building elements and enabling their identification and selection within a high-fidelity, navigable 3D environment. Two Internet of Things (IoT) air-quality sensors were installed on the ground floor of the building, and their live temperature and humidity readings were mirrored onto virtual sensor replicas positioned at the corresponding physical wall locations within the 3D scene, updating in real time as conditions in the building changed. The resulting digital twin is accessible through an interactive, web-deployable, VR-compatible viewer that allows users to explore the building and observe environmental conditions as they occur. The findings demonstrate the technical feasibility of coupling IFC-preserved BIM geometry with live IoT data streams inside a game engine, and the paper discusses implications for building management, occupant wellbeing and sustainability, together with limitations and directions for future work, including expanded sensor coverage and predictive analytics.