Building digital twins for smart cities: a case study in greece

The recent emergence of the Internet of Things (IoT), the latest technological innovations and the widespread use and embrace of Building Information Models (BIMs) offer several new ideas and decision-making capabilities throughout the life cycle of the built environment. The ability to connect and monitor data from sensor networks remotely in real time as well as the simulation and optimization of engineering systems, have led to the emergence of the Digital Twin (DT) concept of the structured environment. Although BIM lacks semantic completeness in areas beyond the scope of building modelling such as control systems, cadastral systems, networking of sensors, meteorological networks, etc., the DTs aim to achieve the synchronization of big data from various sources and simulate the real world into a virtual platform for the seamless management and control of the construction process, facility management, environmental monitoring, disaster management and disaster prevention, and other life cycle processes within the built environment. DTs in the built environment are still in nascent stages and thus a more in-depth investigation is required to explore and establish the best practices and technologies to serve this evolution. In this paper, we propose a methodology for providing the DT of a building; by crossing from the BIM static world to the dynamic cyber-world of DTs. A practical application is implemented for a two-storey 'smart' building with sensor systems installed in its assets and in the surrounding landscape area. As the practical experiment is successfully completed, we conclude that such an endeavour can actually be achieved at building level offering several economic, environmental and social benefits.