Integrating Lidar and Virtual Reality for Safe Building Condition Assessment

Material recovery tasks in buildings aimed at reducing Construction and Demolition Waste (CDW) require full access and accurate material inventories. However, the structural condition of these buildings may pose safety risks to inspectors, making it essential to minimize on-site exposure while maximizing data acquisition. In this context, LiDAR technology enables the rapid capture of precise 3D geometries, which can subsequently be inspected remotely. This work presents a framework for assessing building conditions through Virtual Reality (VR) based on LiDAR data. High-resolution point clouds acquired with a Handheld Mobile Laser Scanner are combined with virtual markers positioned using Mixed Reality device Microsoft HoloLens 2. Both datasets are registered within a unified reference system and rendered in a VR environment. In addition to true-color RGB visualization, a Multi Feature Synthetic Color technique is implemented to highlight geometric features of the point clouds, enabling the immersive evaluation of the condition of materials. The proposed method is tested in two case studies developed within the European project SUM4Re: a residential building in Longyearbyen (Norway) and a metro station in San Sebastián (Spain). The results show that VR is suitable for remote inspection based on point cloud data. Furthermore, synthetic color can complement original color visualization in immersive digital scenarios. However, tests highlight the importance of adapting the algorithms designed for 2D rendering to 3D environments.

Keywords: Digital Twin, Immersive Visualization, Structural Health Monitoring, Human-Computer Interaction, Augmented Reality, Sustainable Deconstruction.