Exploring Constructive Solid Geometry for Building Reconstruction from Point Clouds: Preliminary Results

Abstract. As-built BIM reconstruction supports building digitalization, enabling efficient management and maintenance of existing buildings. Manual reconstruction from point clouds is both error-prone and cost-intensive, while automatic reconstruction remains challenging despite recent advancements. This paper explores the use of Constructive Solid Geometry (CSG) for automatically reconstructing IFC-compatible models from indoor point clouds of existing buildings. The proposed approach starts with segmented point clouds corresponding to rooms, doors, and windows, then CSG operations are used to reconstruct key building components as solids, including slabs, walls, doors, windows, and interior spaces. These solids are subsequently converted into corresponding IFC entities. The method is evaluated using two case studies, achieving a centimetre-level accuracy and a runtime of approximately 9 seconds per case study. The proposed method provides a promising ability to advance the Scan-to-BIM pipeline, as it enables accurate reconstruction of building components while preserving topological relationships during an efficient runtime.