IFC and QGIS integration for the Integrated Water Service Management

Abstract. Integrated Water Service (IWS), which combines water supply and wastewater treatment, requires complex geometric and semantic management. Building Information Modelling (BIM) and Geographic Information Systems (GIS) are the two main geospatial technologies involved in this field. In very simple terms, BIM allows to have 3D models with detailed geometric and semantic information, and GIS permits to geolocate and manage the models in the territory. To facilitate the integration of these two systems, we propose to manage the BIM models through a standardised relational database. In the BIM world, relational databases are not yet widely used, but the technology is already available. For example, ifcSQL is an encoding of the Industry Foundation Classes (IFC) data model for a relational database. This article proposes an extension of the ifcSQL database with the added possibility to store the georeferenced explicit geometries of the IFC models. Additionally, we present a prototype to make such IFC-based data available via QGIS. In this way, a user can interact with BIM data using open GIS technologies. As a result, it is possible to visualise the models in 2D and 3D, and to perform queries on their attributes. A set of real-world case studies has served as testing ground to develop the functionalities that allow for the interaction with the BIM models via QGIS. Such test cases originate from interviews with a company that manages IWS in Northeast Italy.