Air Quality Monitoring in a BIM model by means of a IoT Sensors Network

BIM (Building Information Modeling) is an object-oriented approach for the digital modeling of buildings and infrastructures, a centralized system for sharing technical information among all Stakeholders during the entire life cycle of the structure. BIM is at the same time a tool for planning, evaluation, monitoring and documentation; however, some constraints determine a potential gap between represented reality and actual reality. This gap is determined by the fact that the information within the system is updated manually by expert designers, losing substantial synchronization with the real system under analysis. The risk is also to have a so extensive dataset to make its update management complex for a human user. Currently, to achieve direct interaction between civil structures and digital modeling systems, the scientific community is carrying out researches for the application of digital twin concepts in the field of construction automation. In particular, studies about the integration between IoT sensor networks and BIM start to be explored. The project described in this paper aims to propose such integration with a specific focus on air quality parameters monitoring, leveraging on scalable approaches. The data updating system is based on a distributed IoT sensor network, designed and implemented using free and open-source software; the communication protocols are all based on open broker-based technologies, like MQTT, and the data dashboard aimed to visualize real-time data and historical data series are based on web applications over HTTP. The research project led to the creation of a sensorized and BIM-modeled hub which demonstrates the validity of the concept.