The Field Trip for Measured Survey of Built Heritage carried out by Tianjin University every summer aims to educate students in each practice session, i.e., on-site data acquisition, condition investigation, classification of the component library, taking observation notes, and accomplishing HBIM deliverables. Under the risks posed by the ongoing COVID-19 pandemic, the students could not leave the campus as a provisional arrangement. Only a team of five people was allowed to visit the Kuiwen Pavilion in the Temple of Confucius (Qufu, China). Therefore, the field trip for students had to be replaced with remote solutions, which consists of the following methods: on-site data acquisition; post-processing; online education, observation, modeling, delivery. Kuiwen Pavilion in the Temple of Confucius is a library with the official architectural style of the Ming and Qing Dynasties (14th to 20th century), for which building regulations are commonly recognized, and are suitable for survey education. In this context, this article focuses on the remote practice methods applied and tested throughout the case study. During the practice of the course, students who managed to finish the course, through the virtual tours and other online methods, finally achieved delivery of the HBIM models.

Historic building information modeling (HBIM) provides an index frame for digital documentation of the cultural heritage, as a continuous process of reverse engineering. The index frame should be a regular model, with a clear comprehension of each component; consequently, associated knowledge could be live-updated with the investigation progress. Therefore, the method of data registration stresses its importance. The axis is fundamental for Chinese traditional architecture as the basis for positioning all components in wooden structures. However, displacement often happens. To correct the displacement while modeling, the hypothetical axis should be determined first. This paper thus proposes a method of generating the regular axis from irregular column grids and aims to develop an automatic solution that is repeatable and transplantable. The finite element modeling (FEM) abstracts the actual problem to enable numerical calculation. Starting from a candidate solution, the genetic algorithm calculates a solution closest to the expectation from the possible solutions in several minutes. The standard deviation is used to measure the amount of displacement based on the hypothetical axis, which is expected to be minimum. This method is compatible with most kinds of input data, e.g., point cloud, excel data, 2D drawing, mesh model, etc., and applied to a World Heritage Site in Qufu (Shandong, China). The results show the displacement of columns with visual expression and numerical analysis and prove that the proposed method is repeatable and traceable and can easily be applied to different projects by changing input parameters.

Keywords: HBIM, Condition Inspection, Dual-route Workflows, Information Management, Interactive Model, Defects Keynote Dictionary This paper explores the BIM-based route map and workflows for documentation of condition inspection for architectural heritage, exemplified by an on-going conservation project of three Duty Rooms in Yangxin Hall complex in the Forbidden City, Beijing. Since intensive, multi-disciplinary inspection work for architectural heritage will result in huge amount and categories of data and information, the 2D-based traditional way of documentation is abandoned, while HBIM was introduced for information management and presentation. In respond to multi-disciplinary collaboration, a duel-route workflow is specially developed for the combination of BIM and non-BIM teams, in which the BIM team is responsible for BIM models’ creation and maintenance, and for information management and presentation, while the non-BIM team carry out the survey and inspection in their own established way without any requirements for BIM skills, making a little adjustment where necessary, with interactive models as links between them. The practice following the workflows mentioned in this paper proves that condition inspection based on HBIM is applicable, compatible and flexible, providing the possibility to improve the traceability and sustainability of heritage information, and to generate visualized, thematic and integrated presentation in high efficiency and consistency. This paper also provides some solutions to the specific problems encountered during actual operation. For example，the defects keynote dictionary offers a sound tie between the BIM team and non-BIM team, and between site survey and final presentation; the application of shadow elements helps to improve the information management between whole and parts, ideal and actual, 2D and 3D.

Historical Building Information Modeling is a digital modeling technology applied to cultural heritage buildings. It has made remarkable progress in aspects such as data integration and management, digital protection of historical buildings, parametric and semantic modeling, multi-source data fusion, and interdisciplinary cooperation platforms. However, the sustainability of this technology has not been explored yet. This paper analyzes nearly a hundred related research achievements between 2010 and 2024 and finds that there is not only a lack of a review of the development and application of Historical Building Information Modeling (HBIM) technology in China, but also a serious shortage of discussions and explorations regarding its sustainability. Therefore, taking the development and application of Historical Building Information Modeling technology in China as the research scope, using relevant practical projects and research achievements in China, and combining a small number of the latest foreign achievements as cases, centering around the research question of the sustainability of Historical Building Information Modeling, this paper adopts the methods of review research and comparative research. It sorts out four development directions and the faced dilemmas in the development process of Historical Building Information Modeling in China and puts forward constructive suggestions for sustainable development, as well as a set of theoretical paths for the sustainability of HBIM technology based on Revit (version 23.0.1.318), Dynamo (version 2.17), Python (version 3.12.1) (Open 3D v0.18 and PointNet++), Network Attached Storage, and cloud-based collaboration platforms. The purpose is to provide a referable path for the sustainable development of Historical Building Information Modeling technology in China.

The investigation of cultural heritage is a continuous process, in which a large scale of metadata is gradually accumulated, i.e., condition data, intervention data, and the comprehension of building techniques. We take the roof tile of Yangxindian Palace as an example. The total number of roof tiles is 17,154. Their positions are various, as they are equally distributed on double-curved irregular surfaces. Their metadata are multisource and heterogeneous. Therefore, the integration between the model and the data can be complex. This paper aims to generate the M1 (metalevel) model with its graph database based on the M3 (metalevel) model through algorithm modeling. This synergy approach consists of three parts. First is the data collection. The unique identifier is used as the index while investigating onsite, which eventually forms the metadata repository. Second is the algorithm modeling. All the roof tiles are rebuilt in Grasshopper with identifiers. Their metadata are merged through Cypher syntax, which can generate the graph database in Neo4j. Third is the delivery. The IFC model and knowledge graph are connected in real time during the whole process. The significance of this paper is to provide a synergy approach and discuss its efficiency for the integration between a model and data of very large quantities. The results show that it is efficient to express the semantic relationships of both conditions and interventions. It is practicable to lightweight the IFC model and to associate metadata into the graph database, enabling online browsing and querying.

In heritage recording, conservators are required to understand the subjects, that, in a sense, means to recognizing the two opposite aspects of the buildings in question: regularity and differentiation. To do a specific documentation work, one has to make balance between regularity and differentiation – the opposite poles, according to the goals and specific needs of the work. This paper discuss the goals and needs of HBIM, and regards HBIM models as “index frames” to run the information management for heritage. Therefore regularity is preferred in HBIM and the question of “regularized reconstruction” are raised. Three examples are provided to demonstrate how to realize the representation of regularity in preparing HBIM models, resulting in the conclusion: 1) partial or global regularized reconstruction is available and efficient; 2) regularized reconstruction can make best use of the advantages of BIM and bypass the disadvantages; 3) to what extent the use of regularized reconstruction depends on the regularity degree of the subject.