BIM for Renovation: An Insight (Part – 2)
This is the concluding part of the blog BIM for Renovation: An Insight (Part – 1). In the previous blog, we had discussed how Building Information Modeling is beneficial for creating new buildings as well as in renovation projects. We had understood how the procedure for BIM Modeling is different in renovation projects as compared to constructing a new building. We had discussed a scenario wherein the 2D drawings of the as-built condition were available and they were utilized to create architectural, structural, as well as the MEP model. These models were then used for Clash Detection and BIM Coordination.
In this blog, we will consider the other scenario where the existing drawings for the as-built condition are not available. In order to capture the as-built conditions, a high-definition 3D laser scanning of the building is carried out. The point cloud data generated is accurate and the actual dimensions of the existing building can be measured from the scans using software like ReCap. Thus, the point cloud data serves as a starting point to create the BIM model.
Consider this scenario wherein a lakeside dam was to be renovated in the US. Taking into account the nature of the project, it was evident that it was a very challenging project and precision was critical here. We had to show cracks in the dam face that were picked up by the scanner as well as the walls, outflow ledge rock, and surrounding areas. The area included created a BIM model of the dam on the lake-side to the water level, ledge under the water that extended out into the lake before the lakebed starts, as well as the lakebed points. The site was very huge with an area spanning up to 10,000 acres.
Given the volume of cracks, voids, and extrusions that were present in the dam, it would have been difficult to capture all them in the traditional method of renovation. However, with the use of Scan to BIM Modeling, all the anomalies in the dam building were captured meticulously. Even the large stones that were present at the dam site were modeled to show the cracks and contours on its surface. Thus, the resultant BIM model had all the critical information about the existing conditions which will be eventually used to re-design and renovate the dam.
Conclusion:
Utilizing BIM Modeling Services has benefitted the construction industry to a great extent. Whether it is employed in a new project or a renovation project, BIM has helped contractors and sub-contractors reduce their costs and increase their efficiency. For renovation projects, the best way to complement the BIM workflow is to create 3D BIM models based on the As-built information either in the form of CAD drawings or point cloud data. These models serve as the starting point for schematic design.
Bhagwati Pathak
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