Technologies and techniques in digital twins for real-time data visualisation in building maintenance: A state-of-the-art review

Digital Twins (DT) and Mixed Reality (MR) technologies are emerging as transformative solutions for automating processes and visualising real-time IoT sensor data in building operations and maintenance (O&M). However, current implementations predominantly rely on 2D or static 3D interfaces, limiting visualisation, immersion and data interaction. Though MR can improve data visualisation, its integration with DT technologies is still in its infancy in building maintenance. A systematic review of 55 academic studies provides a critical and in-depth analysis of existing research on DT applications for real-time monitoring and maintenance, visualisation tools, platforms and techniques, MR applications, and related challenges in building O&M. The review identifies a key gap: existing DT-MR frameworks lack sufficient scalability and standardisation required for broader adoption in building O&M. The paper proposes future research directions toward developing immersive DT-MR frameworks that enhance understanding of these technologies in enabling automated, interactive, and visually enriched building maintenance workflows.