Combining HBIM and AR for Heritage Conservation. From Digital Survey to an Interactive Management Tool

Abstract. This paper presents a Scan-to-HBIM-to-XR workflow aimed at supporting preventive and planned conservation of complex architectural heritage. The proposed methodology integrates multi-source 3D surveying, semantic information modelling, and Augmented Reality (AR) technologies into a unified operational framework. Terrestrial Laser Scanning (TLS) and UAV-based photogrammetry are combined to generate an accurate and georeferenced digital replica, which forms the basis for the development of a semantically enriched HBIM model. The model is structured to integrate geometric, historical, construction, and diagnostic data, including quantitative indicators for assessing masonry quality and conservation status. To enhance accessibility and usability, the HBIM dataset is connected to a lightweight AR application that enables on-site consultation and updating of alphanumeric BIM data. Through spatial alignment with the real architecture, users can document degradation phenomena, create AR-based segmentations and georeferenced annotations, and transmit updates to a cloud system, where they are automatically integrated into the HBIM model, ensuring a continuous feedback loop between field activities and the central model. Tested on the historic city walls of Fano (Italy), the workflow demonstrates how HBIM and AR can be combined to transform digital models into dynamic decision-support tools, bridging the gap between documentation, monitoring, and long-term heritage management.