Let’s begin this column on construction with some demolition: We’re going to destroy a stereotype.
You’ve probably heard of BIM (Building Information Modeling). Perhaps you’ve wondered how you might use it in your business. But BIM is not a product. You can’t purchase it from a dealer or online; nor will you find it in a box or on a DVD.
BIM is the combination of technologies, people and processes that support the development and exchange of information for building construction and operations. Just as each project is unique, the concept and application of BIM varies with the needs of the project’s stakeholders: owners, contractors, designers, project managers and suppliers. Each of these constituents plays a specific role in the overall project and uses different skills and technologies to complete their tasks and deliverables.
While the technologies are interesting, the most important concept within BIM is the interaction and coordination between the people working on the project. With such a wide variety of skills and tasks, the exchange of information and instructions must be fast and accurate. This is best carried out at the interpersonal level, ensuring that the appropriate information is provided when and where it is needed.
Often, the information must be carried across multiple disciplines and trades. For example, a project’s structural engineer needs to talk with rebar detailers, concrete contractors or steel fabricators. These people use different terminology, processes and tools than the carpenters, plumbers and other trades who work in the same projects. Yet their work must fit together. That’s one of the important benefits (and challenges) of BIM.
Today most BIM projects are specified through the owner or architect; some are initiated through the general contractor. The BIM execution plan is set out in the contract documents that frame—from the owner’s perspective—the actual project and cover the process from pre-construction through occupancy. The plan defines the project’s physical concepts such as formats and technologies for design and implementation. It also lays out the approaches for the human interactions that drive the project’s success. Most importantly, the BIM plan is developed from the bottom up. Stakeholders develop the goals and processes and then determine which tools will provide the best fit and outcome.
Trimble’s Direct Experience
Why is Trimble interested in BIM? We’re in our third decade of developing and merging technologies and processes for measurement, information management and visualization. These capabilities include the systems for mapping and control during the early stages of a project, as well as instruments and software for layout and checking of structural elements, MEP and other building components.
But that’s just the beginning. Over the years, we’ve extended our capabilities to the 4D and 5D aspects of building construction, including tools for design and construction coordination, planning, estimation, project management and analytics. Our objective is to enhance stakeholders’ productivity and profitability throughout the design-build-operate lifecycle.
To illustrate the value of BIM, Trimble utilized BIM tools and processes for the design and construction of our new Trimble Rockies Campus in Colorado. Completed in spring 2013, the project provided a start-to-finish window into how construction projects operate. One of the most important facets is the interaction between project participants. It’s reinforced the importance of the people part of the BIM triad. The project repeatedly showed that getting the right information to the right person—at the right time—provides benefits that can cascade far beyond the original users.
A critical part of the BIM process and interaction is the development and use of a constructible model. By using Tekla Structures for the structural design model, contractors could maintain a seamless and simple transfer of information to both fabrication and field placement. This constructible model also ensured that field execution matched design intent.
Results from the new building demonstrate that the payoff is real. For example, during construction our contractors needed to alter the delivery schedule for structural steel because the crews worked faster than expected. By correlating design work and using modern field technologies, contractors could place footings, foundations, pile caps and anchor bolts with high accuracy. The accuracy allowed the crews to place the steel accurately and correctly on the first try. This produced time savings not only during the steel erection, but for the rest of construction as well. Because of the accuracy in placing the building’s superstructure, all of the subsequent processes could move faster and with fewer problems.
Information Mobility—The Growth of BIM
One of the strongest trends in BIM is moving information out to the users in the field. Workers on the jobsite must have correct information, or they won’t be able to accurately implement the design in the field. Using conventional methods and 2D drawings or incorrect design models opens the door to errors and rework.
This can be solved by efficiently moving information—design, instructions and results—throughout the different areas of BIM workflow. Information has typically flowed between office and field trailer; it’s now extended onto the jobsite. For example, to extend the BIM process to the field we've incorporated 3D tools into field systems that allow users to see attributes and 3D models on site. This utilizes technologies for data communications, collaboration and visualization as well as measurement and layout.
The information needs to flow in two directions. It’s now possible for trades contractors to collect QA/QC information in the field and move it quickly back to the office. Project managers use this data to verify that the work was according to the design.
The Geospatial Professional’s Role in BIM
In many building construction projects, the work of surveyors and other geospatial professionals focuses on the early stages of the work. Once a surveyor has mapped a site and set control, contractors prefer to handle most tasks for measurement and positioning. So what can a geospatial professional do to take more advantage of BIM?
One of the geospatial professional’s most valuable services is to deliver information that is readily utilized by other systems on the project. For example, georeferenced 3D data enables site designers and architects to be more efficient in their work. Similar data can be used in designing utilities, drainage and access for project construction and operation.
In the U.S. market, BIM presents significant opportunities. In the next three years, it’s estimated that 70 percent of U.S. building projects will be renovation or repurposing of existing structures. Many of these projects will use BIM and will need dense, detailed information about the existing buildings. Geospatial professionals are nicely positioned to provide this information by using 3D scanning, photogrammetry and conventional surveying techniques.
Perhaps the best opportunity in BIM comes through developing a deeper knowledge of building construction. By understanding your clients’ needs and workflows, you can weave your organization into the technologies, processes and people that produce a successful project.