Indoor spaces differ from outdoor spaces in many aspects. Basic concepts, data models, and standards of spatial information need to be redefined in order to meet the requirements of indoor spatial applications. The proper representation of indoor spaces is a key issue for indoor spatial information modelling and analytics. In recent years, the topic of 3D geospatial indoor modelling has been the focus of attention for location-based services and indoor navigation [42,43,44]. As the risk of COVID-19 virus transmission is higher in indoor environments, indoor space modelling is an important topic that facilitates the interoperability between different indoor and outdoor data collection methods and builds a consistent framework for collaborative research and development of the IoCT.