As cities grow denser, Land Administration Systems (LAS) must evolve to represent complex, multi-level property ownership, particularly in apartment buildings. While Building Information Models (BIM) are commonly used for 3D representation, their availability remains limited for many buildings. This research explores the use of point clouds as an alternative means to represent 3D spatial units in LAS, focusing on the integration of cadastral floor plans and the Dutch national point cloud dataset (AHN).

Three apartment cadastral drawings from different years in Rotterdam serve as case studies. The proposed methodology involves four main steps: (1) parsing floor plans using image processing to extract cadastral room boundary polygons; (2) generating synthetic point clouds by extruding floor plan polygons and aligning them with AHN; (3) storing these 3D spatial units in a PostgreSQL-based database following the ISO 19152:2024 Land Administration Domain Model (LADM); and (4) developing a web-based 3D LAS using Vue.js, Cesium, and FastAPI for visualization and interaction.

Results show that room boundaries can be extracted and converted into 3D point clouds for integration into a cadastral database. The synthetic point clouds include room-level attributes and spatial identifiers, enabling interactive visualization and data management through a web interface. However, challenges such as misalignment due to occlusion in AHN data and inconsistent quality in older floor plan drawings affect the accuracy and automation of the process.

This research demonstrates that point clouds can effectively serve as final 3D representations in land administration, providing a scalable solution in the absence of BIM models and minimizing the need for additional field surveys.