Open GIS-to-BIM-Converter - LKMap 2025 Data to IFC 4.3 Data

Underground utility networks in Switzerland are typically managed using normed formats such as the SIA 405-INTERLIS standard within 2D Geo-Information Systems (GIS). However, due to the increasing demand for 3D representation, particularly in the context of Building Information Modeling (BIM), there is a need to represent these networks in a 3D format. This research project focuses on the SIA405_LKMap model, which describes the minimum information required for cadastral registers and is currently being revised to support 3D Geo-Information. The research presents an evaluation of the recommended changes in the revision of SIA405_LKMap and a Python Command Line Interface (CLI) prototype that enables the conversion of SIA405_LKMap data into valid 3D data in the Industry Foundation Classes (IFC) format.
The resulting prototype has a CLI that requires users to input a INTERLIS LKMap transfer data file and a reference null point, while also providing other optional arguments. The provided arguments are validated, and the conversion process is performed using Python libraries such as Pyogrio and IfcOpenShell. The resulting 3D data includes element attributes as IfcPropertySets and the visualization of geometric uncertainties.
The prototype provides a strong basis for future development. The outlook includes additional improvements, such as optimizing geometric representations and adding configurability and extensibility features for users. Overall, this thesis demonstrates the feasibility of converting INTERLIS LKMap data to the IFC 4.3 format, opening up possibilities for improved representation and visualization of underground utility networks in the field of BIM.

Keywords: 2D to 3D conversion, INTERLIS, LKMap, IFC, Python CLI, GeoPackage, Building Information Modeling (BIM).