3D point cloud data from data acquisition techniques such as terrestrial photogrammetry, close range photogrammetry (CRP) and light detection and ranging (LiDAR) play a major role in heritage because of the large amount of information they provide. This data includes the metric accuracy of the objects surface, reflectivity information and materials texture. The point clouds can be exported to Building Information Models (BIM) to simplify the 3D modelling processes, thus becoming part of the restoration and reconstruction project. Currently, most scientific works in the field implement insertion procedures of point clouds into BIM, whose interoperability should be analysed in order to reveal its usefulness in heritage buildings modelling. This paper reviews the scientific literature on the integration of Terrestrial Laser Scanning (TLS) and Structure-from-Motion/Multi-View Stereo (SfM/MVS) data into HBIM. Despite having been investigated, this field lacks a methodological structure regarding the integration of point cloud data into HBIM.

The digitalization of the historical-architectural heritage for virtual reality (VR) applications is crucial within the contemporary scientific and technical debate for several aspects. In fact, beyond the exploration for education and entertainment purposes, the employment of three-dimensional (3D) reality-based and computer-based models and environments seems to be very promising for performance assessment and risk management as well. Particularly, in order to develop and validate smart, low-cost and user-friendly tools, which might apply even in cases of limited time and budget, the present paper is going to propose a methodological workflow based on thematic virtual tours of 360° scenes, which integrate a variety of informative contents and digital products as external hotspots/switches. The VR tours, where 3D models might play a key role for an accurate representation of relevant parts and/or analytical elaboration of further data, are conceived as flexible and scalable solutions, supporting users, technicians and authorities through remote access, diagnosis of the state of conservation and communication of safety measures. The application of the proposed methods and techniques to a representative case study, the Norman-Swabian Castle of Gioia del Colle (Ba), South Italy, is presented in order to illustrate the achievable results and highlight the benefit of innovative “digital” solutions for data collection, storage and communication, compared to the traditional “analogical” practices. In detail, a Web-GIS platform, developed within a previous research project, is integrated with direct links to three thematic virtual tours that provide added contents for inclusive dissemination (timeline schemes, aerial views, 3D sculptural and architectural details), performance assessment (diagnostic reports, decay maps, 3D reconstructions of technical components) and risk management (exit signs, help instructions, warnings). Thus, the VR tours, while documenting realistically the state of the site, might act as host environments of digital products, at increasing complexity, all displayed according to an intuitive and accessible communication approach.Highlights:• Virtual tours of 360° scenes, linking thematic digital contents, are proposed as intuitive and versatile tools for smart documentation, conservation and protection of historical buildings.• The role of 3D reality-based and computer-based models is discussed toward their integration and correlation within thematic virtual tours of 360° scenes.• The potential of immersive environments for sharing knowledge about conservation issues and training users on safety measures in historic buildings is underlined.

The digital transformation of the construction sector is also involving cultural and architectural heritage conservation management to solve criticalities of information exchange in refurbishment/restoration, from the preliminary steps until the execution and monitoring of interventions. Nevertheless, time and resources required to complete digital models (point clouds, 3D meshes and HBIM model) are extensive and this can cause interruption of knowledge communication among professionals. The VERBuM project (Virtual Enhanced Reality For Building Modelling) aims at investigating how a central Virtual Technical Tour (VTT), would guarantee a continuous stream of information when other disruptive technologies are integrated in the process and their related products are linked to the VTT. The use of a VTT, based on 360° photos, may fill time and resources gaps as it is a rapid up-to-date and high-fidelityto-reality tool. The fostering of the paradigmatic change in refurbishment/restoration process requires the development of all-in-one digital environments for digital twinning of cultural and architectural heritage and its assessment, aware of potentialities and criticalities to be overcame. The research moves from stakeholders’ information requirements to implement the VERBuM process supported by the central VTT, editable via cloud-based platform (VERBuM product) to exchange digital contents, uploaded in different file format, but consulted in VR by all the involved actors via web services, without any software product installation. The tool has been evaluated via SWOT analysis supported by Task-Technology Fit (TTF) model and users’ perceptions. The results provide mitigation measures of threats related to distrust in use of VTT within working groups and fruition of point clouds, meshes and BIM models, possible via WebGL-based libraries.

Recently, the scientific community is working on Historic Building Information Modelling and Management (HBIMM) in order to improve the interoperability among information/data in different types and formats. This circumstance has traditionally led to difficulties and errors in knowledge, diagnosis and refurbishment. The proposal of the operative method has been tested for managing the historical buildings’ knowledge system by using relational databases and time parameter creating a 4D-HBIMM simulation for diagnosis of decay and settlements toward data computing. The information, as BIM parameters, refers to historical and constructive evolution, previous interventions, crack patterns and degradation condition of an Augustinian Monastery (southern Italy), as a sample of an agglomeration of buildings, interested by previous refurbishment interventions, decay and kinematic movements. The advantage is the rapid data consultation and the possibility of comparison between geometric-typological and pre-diagnostic information in order to understand the actual causes of the decay and kinematic settlements.