Bridging reality and simulation: Lidar VS. Photogrammetry for fem-ready BIM models

Through a case study of the Higher Polytechnic School at the University of Burgos, this study compares two point cloud acquisition methods: photogrammetry and LiDAR. The objective is to evaluate which technique offers higher geometric fidelity and suitability for downstream thermal simulation workflows. A dense photogrammetric point cloud was generated using images captured with a Canon EOS R5 mounted on an aerial pole and processed in Agisoft Metashape. In parallel, a terrestrial LiDAR scan was acquired using a Leica BLK360 and processed with Autodesk ReCap Pro. Both datasets were analyzed and compared in CloudCompare, using the LiDAR scan as the geometric reference. The analysis focused on detail accuracy, noise levels, and occlusions. While photogrammetry delivered strong visual detail, particularly on flat surfaces, the LiDAR scan exhibited superior geometric consistency across the full façade. Based on these findings, a high-level-of-detail BIM model was manually reconstructed and embedded with a conformal mesh suitable for finite element method thermal simulations. This methodology supports the optimization of reality capture workflows for architectural applications, emphasizing the importance of mesh readiness and graphical fidelity in generating accurate, simulation-ready models for environmental analysis.