Historic Building information Modeling (HBIM)
What is Historic Building Information Modeling (HBIM)?
The preservation process of historical buildings involves surveying, restoration and restitution phases. There are frequent revisions to plans, the process is long, and there are other specific problems. Apart from the difficulties of the process itself, there are also archiving problems at the end of it. In recent years, research has been carried out into using the BIM system on historical buildings in order to solve problems more easily and to provide sustainable protection and management. The possibilities provided by the BIM system, such as facilitating coordination between stakeholders and integrating data, made us think that the BIM system could also be used in historical buildings.
The concept of Historic Building Information Modeling was first mentioned by Murphy in 2009. It is the process of enriching and preserving historical and cultural structures by obtaining data, storing semantic and geometric information and sharing information among project workers. Building an object library of historic building information models is the most basic usage area.
Historic Building Information Modeling (HBIM) Working Method
-Data obtained by photogrammetry and laser scanning is collected and processed.
-The historical details are investigated, using sources about the historic building being studied.
-Historical parametric objects are designed.
-After these studies, the project is produced.
Based on the above, it is possible to create projects with 3D models, plans, details and sections, thanks to Historical Building Information Modeling. At the same time, thanks to project parameters and shared parameters, it allows the addition of new information within the objects and the project, changing and editing it.
In terms of historic buildings, the use of BIM is very important in terms of facilitating coordination in the workflow and combining information that would otherwise be difficult to combine.
Advantages of Photogrammetry and 3D Laser Scanning
– Visual checking of fidelity is very easy.
-The point clouds obtained as a result of 3D laser scanning can be overlapped with the model. Providing detailed controls becomes very easy.
-Therefore, the project process is rationalized and the modeling cost is optimized.
-The status of the building on the day of laser scanning is archived.
Working Process in Historic Building Information Modeling
There are four stages in the Historic Building Information Modeling process;
In the first stage, semantic, typological, graphic and morphological data and information are brought together. Then the graphic data is obtained by means of photogrammetry and 3D laser scanning methods. With photogrammetry and 3D laser scanning methods, point clouds are formed that allow us to transfer the scanned object surfaces to a geometric plane.
Historical written documents are used to access morphological, typological and semantic data. These documents provide us with information about the building, such as construction information, materials used, and changes to the architecture of the building from past to present. Utilizing historical data is very valuable in terms of modeling the objects in the Historic Building Information Modeling library. A better understanding of the historic building being studied is gained by creating a Historic Building Information Modeling library.
The second stage of our work process places all the information we obtained in the first stage into a database. It is possible to model the point clouds obtained in the first stage with both manual and automatic methods. The manual method is the direct integration of filtered point clouds into the BIM system. The automatic method, on the other hand, consists of automatic segmentation and creation of parametric objects from point clouds using software plug-ins and specific algorithms utilizable for flat surfaces.
The third stage is the mapping of the information obtained in the first two stages. The integrated point cloud is manually separated to identify the objects to be modeled. Externally created objects and the BIM library are used to model the structure parametrically. The three-dimensional subdivision of the model begins. The reason for this is to put other kinds of information and new items into the model.
Sharing the information obtained from the previous stages is the last stage in the Historic Building Information Modeling study process. Structure-related studies, time and cost analysis, maintenance-repair, energy simulations, etc. can be carried out after the fourth stage.