Building information modeling (BIM) is a set of processes used in the architecture, engineering and construction (AEC) industry to create intelligent virtual 3D models. Over the past 10 years, BIM has developed into a more powerful solution than standalone software products because it breaks down the traditional data silos and provides the functionality for effective collaboration between all project constituents, e.g., owners, designers, manufacturers, builders, etc. As an end-to-end, full lifecycle process, BIM incorporates and moves beyond traditional CAD work flows.
The adoption of lifecycle BIM requires a paradigm shift in how to tackle a project. Long-established processes have designers document their intent and hand off the plans to the next team to build, without including the intelligence that went into the design. A 2D drawing not connected to anything else in a “smart” way is just a visual representation. Therefore, when using conventional design/build methods, information disappears at every milestone.
Full lifecycle BIM encourages the transfer of information across the project lifecycle. These models include a diverse range of information from measurements and materials to electrical and plumbing layouts, which supports multiple activities such as conflict identification, cost estimates and energy efficiency analysis. The result is a more useful model that can be compared to the as-built during construction to avoid or correct costly errors and after construction to assist with efficient operations and maintenance.
Lifecycle BIM at Denver International Airport
In 2009, Denver International Airport (DEN) began a large expansion project that includes a 519-room Westin hotel and conference center (433,000 square feet), public transit center/RTD commuter rail station, an open air plaza and other improvements. HNTB, a nationwide infrastructure solutions firm, was an integral part of the Parsons-led program management team and was tasked with implementing lifecycle BIM. To complete this requirement, close collaboration and participation from all stakeholders throughout the design and construction process was necessary. BIM technology aided in spatial coordination, clash detection, structural design analysis, design review, cost analysis and construction scheduling. Now a BIM team on staff at DEN continues to use the comprehensive model for operations and maintenance.
“There were a number of factors at play in our adoption of BIM,” says Brendan Dillon, BIM manager at DEN. “First among these was the shift in the industry as BIM was being adopted to improve design and construction processes. When that kind of shift happens, you can lead, you can follow, or you can get left behind. DEN chose to lead. At the same time, the airport was shifting from being a new facility to one that needed more maintenance on more assets and buildings, and we asked the question, ‘How can we maintain our facilities more intelligently?’ The third factor was opportunity. The hotel and transit center project represented a huge infrastructure expansion for the airport, which gave us the opportunity to get a level of data from a significant project that we'd never been able to get using older CAD processes.”
“The advantages of BIM are most apparent on large, complex projects that benefit from collaboration between team members,” says Will Lineberry, director of design technology at HNTB. “On the DEN project we had over 40 design consultants contributing content, and over 200 firms in total working on different phases. We were co-located on site to promote communication and we scheduled meetings to coordinate, which also helped keep everyone on track.”
Obstacles to BIM Adoption
Although the BIM workflow delivers many advantages during all phases of a construction project, the upfront costs and learning curve have resulted in incremental adoption. Demand for BIM models is most often seen in the design phase, but as familiarity with the technology increases, acceptance is growing in construction, as well as operations and maintenance on a limited basis.
“I started my career drafting on paper and have experienced the transition to computers, and now to BIM, so I can truly appreciate the advantages as well as the issues that arise,” Lineberry says. “Ten years ago early adopters started using BIM, and in the last five years it has gained widespread acceptance. Some large institutions, such as hospitals and universities, are requiring BIM of their own accord, while others are reacting to requirements initiated by the GSA regarding publicly funded infrastructure projects. … The major obstacle is resistance to changing proven practices that everyone is comfortable with. Changing from a traditional approach to 3D modeling can have a steep learning curve, but once you are up to speed, the efficiencies far outweigh the costs.”
What is Driving the Technology?
The emphasis on controlling costs while minimizing environmental impacts has brought all infrastructure projects under increased scrutiny, which in turn is driving the need for better information, more accurate reporting and improved collaboration between all team members on a project. In particular, government mandates are motivating software firms to develop smarter tools and requiring AEC firms to deliver BIM models for public sector projects.
Several European countries are on a faster BIM adoption path than the U.S., with Norway, Finland, Denmark and the Netherlands already implementing a public procurement BIM strategy, and France and Germany expected to follow in 2017. In the U.K., the government set April 4, 2016 as a deadline for the mandatory inclusion of Level 2 BIM for all public sector construction projects. In Europe, government initiatives have a larger impact on the AEC industry than in the U.S. due to the much higher percentage of national government spending on infrastructure construction. Even though the U.S. General Services Administration (GSA) announced the National 3D-4D-BIM Program in 2003 and mandated BIM for federally funded projects in 2006 at around 10 percent of total U.S. construction spending, the influence was not nearly as large.
“There are two major infrastructure projects in the U.K. right now requiring full lifecycle BIM: Crossrail, a huge railway project in London, and HighSpeed2, a dedicated high-speed railway from London to Birmingham,” says Geoff Zeiss, a geospatial consultant at Between the Poles. “Both are digital projects starting with design and construction, and capturing and preserving a lot of information that can be used in the future for operations and maintenance. The government forecast savings of 20 percent during design and construction, and more than 40 percent savings over the full life of the projects.”
“I also see energy efficiency as a major driver in the development of BIM,” Zeiss says. “To have access to an information-rich virtual model to experiment with the design variables before breaking ground is a tremendous advantage. You can calculate the total cost of ownership for a building, as well as use this model as a data archive for energy-related information throughout the life of the project.”
BIM Bridges Gaps
The traditional design/build process, even with the addition of computers, involves time-consuming manual work and presents challenges in sharing plans and communicating changes between team members. The BIM process adds value and results in a better outcome by enabling the transfer of information between stakeholders, creating more easily understandable visualizations and integrating data about the structure and its facilities in a single model to be used for the life of the project.
Although the industry has seen strongest adoption of BIM in new construction, it has adapted well to use on existing structures. By putting in some extra time, capturing all the available information in an intelligent model can aid future expansions as well as current operations and maintenance. BIM is a useful background model in the development of maintenance schedules to replace HVAC, plumbing, electrical, etc. Once created, derivative benefits of the model, such as energy analysis, are also within reach.
ClearEdge3D, maker of EdgeWise feature extraction software, recognizes the potential for LiDAR and other reality capture technology to support automated modeling and streamline parts of the design/build process. “Our goal is to bridge the gap between as-built conditions and intelligent building models,” says Kevin Williams, CTO at ClearEdge3D. “Much of the built world around us was constructed before BIM became so pervasive. Now that the value of BIM is understood, we see demand steadily increasing as owners and operators strive to leverage BIM in operations by modeling the existing conditions of their plant, refinery, hospital, etc. LiDAR and other reality capture technologies are particularly useful during this process because they record conditions in very accurate detail, which is invaluable to maintenance and other projects when, for example, equipment is replaced or upgraded.“
“EdgeWise helps project teams by establishing a truly accurate representation of the building or plant from which engineers, operators and designers base their efforts,” says David Mills, vice president of marketing at ClearEdge3D. “To speed up the scan-to-BIM process, EdgeWise can produce a Revit model from a point cloud with minimal manual intervention. Going straight to an intelligent 3D model produces better results than traditional delivery methods.”
It is no secret that design intent and as-built construction vary from one another, some times more so than others. The two diverge as the digitally perfect design model is applied in the imperfect real-world construction site. As projects continue into operations, discrepancies between the design model and as-built conditions can render the former altogether unreliable. Owners and operators frequently discard the design model and commission a new effort to build an as-built model for facility management and operations, and other future needs.
ClearEdge3D sees an opportunity to limit the discrepancies and, in so doing, incorporate design intent and BIM into the construction process. “Our new software, Verity, verifies the accuracy of new construction against a design model and identifies variances, missing elements and other potentially costly construction errors,” Williams says. “Think of it as next-generation BIM.”
Process Still in Transition
As an end-to-end process, BIM delivers much more functionality to users over the life of a project than stand-alone software. However, CAD will continue to play a role in architecture, engineering, construction and operation. “CAD is an extremely good tool built over 40 years for modeling geometry and it is very complementary to BIM,” Williams says. “Prominent BIM technology includes geometry capabilities, although not to the degree of CAD. BIM is optimized for intelligence to a greater degree than its more traditional counterpart. They overlap and work well together.”
BIM is on its way to becoming the standard process for new construction; however, in the case of a minor remodel of an existing structure, there is not a pressing need to create a virtual 3D model if CAD data is available. Many larger institutions are already invested in CAD or GIS-based systems so they still want rich CAD data, even as they begin the move toward BIM.
“Currently we are handling 2D paper construction documents that are still required, as well as the new digital models,” Lineberry says. “In the future, owners may accept models as the final deliverable. It’s part of the transition.”
“One important thing to keep in mind is that BIM is first and foremost about improving the flow of information about a project,” Dillon says. “Sometimes the best tool for that is a 3D modeling platform, but sometimes, depending on the use case, CAD is still the right tool for the job. For instance, on our DEN project, many of the fabricators still used CAD since that was what the tools they worked with required. For them, at that time, CAD was the best tool for communicating what they needed to do.”