Building Information Modelling (BIM) is a methodology that facilitates collaboration through the creation and shared use of digital models. These models contain comprehensive information for the entire life cycle of a building. This methodology improves interoperability, significantly enhances planning efficiency, and reduces the need for redundant data entry that often burdens conventional workflows. Since buildings exist in an environment, geospatial data plays a crucial role in various phases of BIM projects and needs to be seamlessly integrated into these processes. To achieve this integration, openBIM projects rely on open standards such as the

Industry Foundation Classes (IFC) developed by buildingSMART International (bSI). However, transforming geospatial data into IFC is a complex task due to the different modeling intents of BIM and GIS. They utilize different paradigms for semantics, geometric representation, and georeferencing. Given this complexity, many software providers have developed specialized solutions to efficiently and accurately transform geospatial data into the IFC format. One such solution is the Feature Manipulation Engine (FME) by Safe Software Inc., an Extract-Transform-Load (ETL) software application widely used in industry, public authorities / agencies and academia.

The research findings are implemented workflows tailored to transform geospatial data into valid IFC models using FME. These workflows will be published as a framework that can be expanded and adapted in the future. In preparation for creating the workflows, decision trees were designed to outline the transformation steps for each data source and create a clear roadmap for implementation. The ETL process is not a simple format conversion or 1:1 schema mapping. It is crucial to effectively communicate the IFC concepts so that non-geospatial BIM modeling and coordination software can interpret the geospatial content generated in the IFC

models effectively, considering that BIM and GIS serve different purposes. Overall, this research highlights the importance of integrating geospatial data into BIM processes and presents FME as a powerful tool for achieving this integration. The goal of this research was to develop automated workflows using FME to transform 2D cadastral data and 2.5D terrain models in different formats into IFC.