A widespread technology in the new-build construction sector, Building Information Modeling (BIM) is not commonly used when it comes to heritage preservation. Researcher Paul Bryan, who works for the Historic England conservation body, argues that BIM can become an invaluable decision-making and management tool for historical assets.
The recent fire at Notre Dame Cathedral in Paris has stressed the importance of the digitization of heritage sites. Fortunately, the cathedral was laser-scanned by Professor Andrew Tallon in 2015, and the combination of BIM and 3D laser scanning offers hope in the arduous task of restoring the landmark.
In the book BIM for Heritage: Developing a Historic Building Information Model, which Bryan co-authored with Sofia Antonopoulou, the authors address the issues of production and the use of BIM for historic buildings, and highlights successful cases of BIM implication in heritage preservation. The book was recently published in Russian.
Bryan runs a team of five surveyors who specialize in applying geospatial survey techniques to heritage. His team advises and undertakes geospatial surveys for Historic England and works with the conservation body’s Heritage at Risk program, which helps protect and manage the historic environment.
A task as sensitive as heritage preservation requires a lot of information to be considered—from a building’s history to its historic layers, material characteristics, and properties. BIM allows for a holistic view of the building. It is capable of retaining different information in different formats—tables, graphs, images, texts, links, etc. “BIM is a mechanism for bringing all the information about a historical site in one place for people to share and collaborate. You’ve got one focal point on data and use that to then manage the structure of the building,” says Bryan. “BIM data isn’t a conventional archive. The idea behind BIM is about sharing and collaboration.”
BIM allows for the creation of a central repository for all historical assets, including both geometric and non-geometric information such as archives, operational data, maintenance plans, condition surveys, archaeological investigations, material analysis, and other surveys. “It’s not just about the condition of the structure. It also can be interviews with people who lived in that building, for instance. That sort of information is important because it gives you another aspect behind its historical development,” explains Bryan.
BIM is not simply a newer version of a 3D visualization tool—it offers more than 3D modeling and digital documentation applications. “BIM is a digital representation of the components, not just the appearance of it, like for example a CAD model. Rather than just representing a wall as a 2D plane, within a BIM model you’ll actually have the actual depth of it,” says Bryan. “BIM emphasizes the importance of the historical condition, fabric information, and if you can get that right or as near to right as you can, then it means that you’ve got the basis for doing a more detailed analysis on the building.”
One of the obstacles with BIM application in the heritage sector is that the process of laser scanning and 3D modeling is expensive. But unlike in the new-build sector, working with historical assets does not necessarily require investing in expensive 3D scanning during the initial stages. “BIM is not just 3D laser scanning and full-blown 3D Revit models. To start using BIM, you can work with the information that is already available. With the sites we work on with Historic England, the information that is initially present is enormous.”
Another problematic issue with BIM application for historical sites is the irregularity of historical data. Existing tools that are aimed at designing buildings from scratch, such as Autodesk Revit, can become less effective when working with historical assets. “If you take a very irregular heritage building, like Stonehenge for instance, you won’t find a flat face, a straight edge—it’s all irregular. It’s possible to fit that within Revit, but it will take an awful lot of time and money—and is it worth it at the end of the day?” says Bryan.
He believes that software suppliers need more research in developing their tools, which can ultimately make it easier and simpler to work with historical data. “I’m fairly certain that these kinds of plugins that extend BIM modeling capabilities like Autodesk Dynamo might help us get the irregularity of heritage within tools that are there that we commonly use already.”
There are a number of organizations that are already implementing BIM. The Natural History Museum commissioned a laser-scan survey of all of its publicly accessible areas and external building façade in South Kensington in London. The BIM-ready Revit model which has been produced can later be used for facilities management, project coordination, and future design work.
Fort Bridge is another successful case of BIM implementation. Work at this heritage site has involved widening sections of an existing road that passes through a sensitive archaeological landscape. “The BIM product allowed users without a background in engineering to see clearly where archaeological deposits could be damaged or lost as a result of the construction of new drainage and utilities diversions,” write Bryan and Antonopoulou in their book. “The use of BIM also aided the design process, as the early detection of archaeological impacts allowed, in some situations, the design team to reconfigure works to avoid archaeological deposits.”
“The adoption of BIM and collaborative work in the heritage sector (both for construction and asset management) requires organizations and individuals to embrace change and accept that traditional roles and practice models may need to be adapted to deliver projects successfully using BIM. At the same time, BIM offers an opportunity for modernization and increased efficiency in the sector, by incorporating digital technologies appropriately within heritage and conservation practice,” he concludes.