Author: @Clara Garcia Moll from UVIGO

At MedGU 2025 in Athens, SUM4Re presented this groundbreaking research, showcasing a low-cost approach to automatically identify construction materials in 3D before demolition. By leveraging mixed reality technology, the study demonstrates how sustainable demolition can become more efficient, accurate, and supportive of material reuse, paving the way for circular construction practices.

This study introduces a low-cost method to automatically identify construction materials in 3D before demolition using the Microsoft HoloLens 2 instead of expensive LiDAR systems. Since the device’s depth sensor has no color, the workflow adds color from aligned RGB images and uses a region-growing algorithm to segment materials.

Two case studies, one in Norway and one in Spain, show that the method works better in controlled indoor conditions (F1‑score 0.86) than in challenging environments (0.51). The approach supports material reuse and aligns with Sustainable Development Goal 12. Future work includes using RGB video, machine learning for seed selection, and integration with BIM tools.