Scan to BIM (Building Information Model)
In this project, we worked to reverse engineer the BBC Headquarters in London. This scan to BIM project required our team to undertake a full measured building survey of a seven storey building using 3D laser scanning and reverse engineering point cloud data to produce the existing phase in Autodesk Revit.
We used Total Stations, chequerboard targets, and GPS receivers to ensure accurate survey control and real world positioning of the Laser Scan Survey Data.
The building was located in central London where two members of our team spent three days surveying the building. The team stayed over in London, which enabled them to spend more time on site per day to get the job done efficiently. We collected a combination of full colour RGB scans, so that we could identify building materials and improve visual presentations, and grey scale scans to enable us to reduce costs and on-site time.
Working with The Scan Data
Once the building had been scanned, we registered and indexed the scan data to .rcp format. However, registering point cloud data can be quite a task as we need to ensure that the alignment accuracy is precise, to allow us to model within the required tolerance of +/-20mm. We then imported the resulting point cloud into Revit to produce the required 3D Model. In total, we collected 377 scan positions to achieve full coverage of the building, this meant modelling in Revit would be much simpler and no assumptions needed to be made.
The Final Stage
The final stage was to create the Revit model to the specifications in the client's brief. During this period, the client requested provisional survey information of the building with specific deadlines so that their workflow would not be interrupted. Some of the client's original requests meant that modelling the building would become inefficient and cause potential errors, so we educated them in the workflow of creating a point cloud from scan data, and worked with them in a way that enabled them to meet their deadlines yet didn’t impact the overall time scale of the scan to BIM project.
We like to keep our customers happy and provide the data they want, which pushes us to work differently depending on the situations presented by each project we encounter. It is important to us to work directly with the clients during a scan to BIM project so that we have a clear understanding of what their needs are, that we may provide the best suitable service for our client.
This model took about three weeks to produce once the scan data had been imported to Revit. For quality control, the work was checked and regularly monitored by our in-house BIM manager who has been working with and developing scanning to BIM workflows for over six years.
The client came back to us requesting further information, which we were easily able to extract from the scan data we had previously collected—this meant no revisit to the site was required. As a bonus, we even produced some screen shots and visuals of their scan to BIM project free of charge. We like to please every client and we set out to work on their requests immediately. This was an exciting survey to BIM project to work on, as we had an opportunity to model this rather complicated, multi-storey building using a great level of detail.