UAV-Based Photogrammetric Reconstruction of a Historical Sugar Factory: A Case Study of the San Joaquín Site (Maro, Spain)

The production of sugar from sugarcane cultivation was one of the most significant industrial activities in eastern Andalusia during the late nineteenth and early twentieth centuries. Along the Málaga coastline, remnants of these sugar mills can still be found, many of them currently in a state of abandonment or poor conservation. This study presents the 3D digital reconstruction of the San Joaquín sugar mill (Maro, Málaga, Spain) using UAV-based photogrammetry. A point cloud was generated from aerial images processed with specialized software. A comparative analysis was conducted using between 12.5% and 100% of the captured images to evaluate model accuracy and computational cost. The full dataset (100%) produced the most complete and accurate model, although at a higher computational cost. Reduced datasets (25–50%) achieved high-resolution representations of the main structures but failed to fully reconstruct certain elements, particularly the chimney. The point cloud was subsequently used to develop a HBIM-based model, enabling the reconstruction of structural components, including a hypothetical interpretation of the workers’ housing, currently in a near-ruined condition. These results demonstrate the effectiveness of UAV photogrammetry and HBIM as complementary tools for the documentation and reconstruction of industrial heritage, providing a solid basis for future restoration and adaptive reuse strategies.