ISPRS-Annals ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences ISPRS-Annals ISPRS Ann. Photogramm. Remote Sens. Spatial Inf. Sci. 2194-9050 Copernicus Publications Göttingen, Germany 10.5194/isprs-annals-XI-4-2026-13-2026 IFC and QGIS integration for the Integrated Water Service Management Berlato Michele 1 Agugiaro Giorgio https://orcid.org/0000-0002-2611-4650 2 Arroyo Ohori Ken https://orcid.org/0000-0002-9863-0152 2 Zanchetta Carlo 3 DTG – Department of Management Engineering, University of Padova, Vicenza, Italy 3D Geoinformation group, Department of Urbanism, Faculty of Architecture and Built Environment, Delft University of Technology, Delft, The Netherlands DICEA – Department of Civil, Building and Environmental Engineering, University of Padova, Padua, Italy 10 07 2026 XI-4-2026 13 20 Copyright: © 2026 Michele Berlato et al. 2026 This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit https://creativecommons.org/licenses/by/4.0/ This article is available from https://isprs-annals.copernicus.org/articles/XI-4-2026/13/2026/isprs-annals-XI-4-2026-13-2026.html The full text article is available as a PDF file from https://isprs-annals.copernicus.org/articles/XI-4-2026/13/2026/isprs-annals-XI-4-2026-13-2026.pdf

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.