Some design and construction firms view building information modeling (BIM) as a new market trend. For the Beck Group, BIM is an integral part of the way we do business. We use BIM through the whole process on every project, from initial design to preconstruction to construction. Applying BIM successfully requires the right tools and strategy. Although BIM is often considered a software-dependent process, hardware components are involved as well; in particular, 3D laser scanning is a key technology for using BIM on any renovation or retrofit project. Following are three tips for optimizing the process when scanning for BIM.
1. Start With a Plan
Scanning for BIM begins with a plan. The BIM execution plan, or BEP, is the standard roadmap for a BIM project and should provide guidance regarding the level of detail required in the models. This information will determine the scan density. Additionally, scanning locations should be identified to ensure proper coverage and avoid shadows and obstructions. These locations can be developed from CAD drawings, site photographs, Google Street View and Google Earth images as well as information provided by the client. The more comprehensive the plan, the faster the scanning will proceed once the team is onsite. However, it’s always a good idea to build in a buffer of contingency scans to ensure that all the data is captured correctly in a single site visit. Remobilizing to capture missing data is costly; fortunately, it can be avoided through proper planning.
2. Use the Right Tools
The right combination of hardware and software can make all the difference in being able to efficiently produce accurate, high-value models. Often substantial productivity gains can be realized by investing in new technology.
Several years ago, for example, the process of developing models from laser scans required using a patchwork of software to compare the Revit model with the scans, measure any differences, make the adjustments in the model, do another comparison, and continue making adjustments as needed. The process was labor-intensive and time-consuming, and it introduced the risk of human error in every manual function.
Why BIM Is Good for Building
• The additional information provided through BIM allows the development of documentation, quantities, estimates and schedules for construction with varying levels of automation.
• Implementing BIM on the jobsite once construction has begun allows on-the-fly interaction to aid in construction, immediate integration of any construction changes, and accurate as-built and revision models.
• With BIM, project teams are able to make smarter, more informed decisions earlier in the design and construction process that result in higher quality and more sustainable projects delivered with less risk, time and cost than conventional methods.
• The implementation of BIM is integral to the success of all design-build
When the Leica CloudWorx for Revit software plugin was introduced in November 2011, it provided the opportunity to use the as-built point cloud data captured by laser scanners directly in Revit, substantially streamlining the process of working with point cloud data. Now, instead of spending one or two days importing and aligning scans in Revit, we simply open our scans in CloudWorx within the Leica Cyclone database, and they’re already registered. The software uses crop settings and crop regions from Cyclone to provide the ability to view more of the model and less of the scan, or vice versa for a different perspective. It also allows us to save and reuse crop settings for faster processing. We can control the number of points that are loaded and the number of points visible based on the crop region. And we have full coloring options, so we can show the scan in color, grayscale or intensity, depending on the needs of the individual user.
Other software tools such as ClearEdge3D EdgeWise and IMAGINiT Technologies Scan to BIM have also continued to improve, allowing us to create complex models from scan data faster.
As we increased our efficiencies in managing BIM datasets, we began exploring the idea of expanding our BIM capabilities by bringing laser scanning in-house. In January 2013, we purchased a Leica ScanStation P20 laser scanner for its ability to scan quickly at high data densities. In about six minutes per scan, we can capture all the data we need to create a high-value BIM. Our hardware and software tools, combined with our expertise, allow us to provide a fast turnaround with an accurate BIM that benefits our clients.
3. Demonstrate the Value
An increasing number of clients have begun recognizing the benefits of laser scanning and asking for laser scanning services on their projects. However, even where it isn’t part of the project scope, laser scanning can offer substantial advantages. For service providers, scanning every renovation or addition project as a standard practice is a worthwhile endeavor that can provide increased efficiencies internally and can also lead to demonstrated benefits for the client later on in the project.
For example, we scanned and modeled a building for a planned precast concrete addition. The laser scan showed that the as-built drawings were off by 2 feet. If the precast concrete wall had been built based on the original drawings, the project team would have had to send it back to the shop to be demolished and recast. Even if the error had been caught before the wall was built, reissuing engineering drawings would have been time-consuming and costly. By laser scanning at the outset, we were able to develop the correct model from the beginning, thereby demonstrating a substantial cost savings to the client and upholding our reputation as a leader in providing innovative solutions.
BIM is an evolving process that continues to improve through experience, the development of standards and the continued advancement of technology. Through BIM, projects are becoming more transparent and more intelligent, with less rework and fewer mistakes. By harnessing tools such as laser scanning, service providers on the leading edge are building intelligent structures faster, cheaper and better.