# HBIM: Background, Current Trends, and Future Prospects
## 3 Standards and Protocols  
Since the beginning of the 21 st century, there has been growing interest among international heritage preservation institutions in promoting modern technologies to digitize tangible cultural heritage as a means of preserving it in the event of the loss of a physical asset. To ensure that these digital versions of heritage assets are reliable, accurate, and representative, some international standards, protocols, and recommendations have been developed in recent years. The International Council on Monuments and Sites (ICOMOS) has been a pioneer in promoting scientific methodologies for the preservation of architectural heritage (Figure 5), and the digitization of historic structures is no exception. In fact, the first international call for the digitization of CH buildings was introduced in the 2000 ICOMOS Charter of Krakow [29], three years before UNESCO approved the Charter on the Preservation of Digital Heritage [30]. Figure 4: Distribution of HBIM-related publications by country (2010–2023). Figure 3: Percentage of HBIM publications by research area in the Web of Science database (2010–2023). These initiatives were further strengthened by the Vancouver Declaration [31] in 2012 and the 2015 recommendation on preserving documentary heritage. In 2017, the International Principles of Virtual Archaeology (Seville Principles) [32] were ratified by the 19 th ICOMOS General Assembly, following the guidance set forth in The London Charter for computer-based visualization of cultural heritage [33]. These standards and protocols outline procedures for digitizing tangible heritage and making these models accessible to experts and the public. However, despite the development of protocols about heritage digitization, the lack of international standards governing the application of BIM methodology to heritage buildings is still one of the most significant challenges that HBIM technology has to face. There is an international standard for BIM, ISO 19650 [34], developed by the Architectural Engineering and Construction Industry, which defines a procedure for the digital management of built assets. The standard includes recommendations for defining a management framework for BIM model information, covering aspects like information exchange, registration, version control, and organization, applicable across the entire lifecycle of a building. It aims to ensure that all information is sufficiently detailed to support decision-making at every project stage. According to the standard, information should be accessible to any user and reliable enough to facilitate seamless exchange between all stakeholders involved in different project phases. However, even though ISO 19650 provides a valuable framework for digital collaboration in BIM, there are certain ambiguities and gaps in the standard, such as the lack of a definition of the specific content requirements for various levels of detail or its focus on new construction, that can pose challenges in heritage applications [7]. Another relevant BIM standard is the Italian UNI 11337 [35], which provides a framework for managing building information modeling processes across various phases and disciplines. This standard outlines guidelines for the structured flow of project information, ensuring alignment between client expectations and project execution. UNI 11337 introduces a unique level of development classification from A to G, combining geometric detail and information quality, and defining essential roles like BIM coordinator, BIM manager, and common data environment manager to streamline team collaboration. Additionally, the standard incorporates BIM's extended dimensions (4D to 7D, covering time, cost, operation, and sustainability), positioning it as a comprehensive tool that supports Italy's evolving public procurement requirements and aligns with international standards while adapting to local industry needs.