Beyond 3-D

BIM Technology is Changing the Industry – Slowly

By Diane Greer

Building information modeling is already the “next big thing” in construction technology. Just how far can it go?

From design to construction planning and throughout the building process, construction teams are broadly applying building information modeling across a diverse array of projects, and it’s transforming the design and construction industry’s project delivery process.

But while BIM is gradually winning industry converts, it has not yet graduated to the mainstream. Challenges remain in transitioning building teams to use BIM, solving software compatibility problems and managing modeling data.

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In the evolution from CAD to BIM, the industry is transitioning from two-dimensional designs and shop drawings to three-dimensional digital renderings of the physical and functional aspects of a facility. BIM provides a shared and integrated resource for all members of the project team, facilitating visual decision-making and fostering collaboration.

“Visually modeling a project early in the design process promotes stakeholder participation and better communication between owners, the design team and other stakeholders in the process,” says Ilana Hellmann, a mechanical engineer with the U.S. General Services Administration in Washington D.C.

Besides 3-D visualization, BIM provides the ability to link building components, such as beams, walls and windows, to the object’s structural characteristics, cost, installation schedule and other data required by project participants.

“When you make a BIM model, you are not just creating a 3-D image, you are creating an image that contains a rich pool of data that can assist you in planning projects, estimating, logistics and developing schedules,” says Denis Leff, logistics manager at New York-based Bovis Lend Lease.

Estimating Costs

A screen shot from the architectural BIM model for Mt. Sinai Center for the Science and Medicine in Manhattan showing the exterior of the facility. (Image courtesy of Bovis Lend Lease.)

Bovis used BIM to estimate costs for the 443,000-sq-ft Mount Sinai Center for Science and Medicine in Manhattan. Quantity counts extracted from the project’s model were loaded into Excel or Timberline to calculate costs. “Estimating costs using BIM is more efficient, but it has a longer learning curve,” Leff says.

While the process is more efficient, it is not totally seamless. Before pulling quantities from the model, building component parameters may require modifications. For example, ductwork will specify size and length but might not indicate if the ducts are low or medium velocity or acoustically lined, Leff adds.

Design Analysis

To minimize conflicts in the field, many teams are employing BIM to identify interferences between the architectural, structural and MEP elements. “Using clash detection as part of an integrated design process, we can get a higher-quality set of design documents and a much more efficient construction process.” Hellmann says.

BIM proved instrumental in identifying interferences and constructability issues during the design of the $800 million Yankee Stadium in the Bronx. New York-based Turner Construction Co., the project’s construction manager, overlaid architectural and structural models with subcontractor-supplied MEP models to help the team identify clashes in the design and facilitate project coordination in the field.

“You see a lot more in 3-D,” says Jan Reinhardt, Turner’s BIM program manager. “We saw clashes and conflicts in the model that we did not see in the drawings.”

As a result of MEP coordination during the design process, the team is seeing significantly fewer conflicts and request for information during construction, he says.

New York-based Parsons Brinckerhoff is using BIM to analyze building performance. A detailed BIM of the MTA’s $13 billion East Side Access project, which will link the Long Island Rail Road in Queens to a new terminal beneath Manhattan’s Grand Central Station, was used for flow analyses, modeling how people will move in and out of the facility and how the ventilation system will take air in and out of the facility, says Rachel Arulraj, PB’s director of virtual design and construction.

The General Services Administration is evaluating the implementation of BIM to assist in energy modeling. An energy-simulation package analyzing the design for the renovation of the Peter Rodino Federal Building in Newark, N.J., used data extracted from the project’s BIM. But “it is not an easy thing to take an architect’s model and insert it into an energy simulator,” Hellmann says.

Adding the 4th Dimension

Linking BIM models with the construction schedule (often referred to as 4-D modeling) is allowing teams to visualize the workflow and evaluate construction sequences.

The design of the $1.4 billion Meadowlands Stadium project in East Rutherford, N.J., incorporates 18,000 pieces of structural steel and 3,200 pieces of precast concrete. In most projects the structural steel is erected first, followed by the precast concrete.

But design of the overhang around the top of the stadium required the precast to be installed simultaneously with the steel, says David Campbell, vice president for innovation and technology at Skanska USA Building, Parsippany, NJ.

By linking the BIM model to the construction schedule, the team was able to visualize the workflow and optimize the installation sequencing, Campbell says

Bovis and PB employed 4-D modeling and animations to evaluate logistics and assess constructability of the $880 million Fulton Street Transit Center. “We linked all the 3-D elements to the schedule and played it out repetitively until we came out with the best schedule,” says Judith Kunoff, chief architect at MTA New York City Transportation Authority.

Process Improvements

A rendering of the finished 443,000-sq-ft facility. (Image courtesy of Bovis Lend Lease.)

Exchanging BIM information with subcontractors and fabricators is saving time and money. “At Yankee Stadium, the steel detailer/fabricator received the steel model created by the structural engineer and used it to complete the connection detailing, prepare shop drawings and prepare the computer numeric control downloads for the machines that cut and punch the steel," Reinhardt says.

All the subcontractors on the project were told to use the model to automatically generate shop drawings. “At first there was a lot of trepidation among our team members, but now they are strong advocates of BIM,” Reinhardt says. “Sharing information between team members has increased the efficiency and the quality of coordination compared to a typical project.”

At the Meadowlands project, BIM is facilitating submittal reviews and tracking. Normally, paper shop drawings for each of the 18,000 pieces of steel would be sent to Skanska and the structural engineer for review and approval prior to fabrication. “That is all happening electronically now,” Campbell says.

BIM, along with Vela Systems software, is facilitating materials management on the project. The precast pieces are manufactured in four different facilities and there are four stages to the installation process, Campbell adds.

Radio frequency identification tags attached to each piece tracks its progress through manufacturing, shipping and installation. At each point in the process, the RFID is scanned and the information is automatically updated in the model.

“Because we have a detailed sequencing process, we need to make sure the factory is working on and shipping the right pieces at the right time,” Campbell says.

Transitioning to BIM

Inside the “IRoom” where construction teams for Turner Construction’s projects gather to display and work on a model during coordination meetings. (Image courtesy of Turner Construction Company.)

Some large owners see the value of BIM and are adopting the process. The New York City Transit Authority plans to use BIM on every design starting in calendar year 2009, says John Reiter, the agency’s deputy vice president of engineering.

“The ultimate benefit of BIM is you get a more efficient and better quality design,” he says. “You get a product that people can visualize, use for constructability and see exactly how to build piece by piece.”

Rehabilitation of the 10th Street Substation will be the first NYCTA project to employ BIM from start to finish. The project encompasses renovation of the structure and replacement of outdated electrical equipment and distribution cabling.

The GSA now requires architects and engineers to submit models with correctly defined spatial attributes during the conceptual design stage for new buildings, Hellmann says.

“We see BIM as the future of the construction industry,” she adds. “The industry is relatively inefficient and we see BIM addressing that problem and getting a higher quality, more efficient product in design and construction than in a traditional process.”

BIM is also becoming a standard within some large construction firms. Turner is fully committed to BIM, Reinhardt says. “We believe that in 2.5 years or so we will do BIM on a majority of projects,” Reinhardt adds.

Bovis sees BIM becoming a standard within the next couple of years, Leff says.

“Industry interest in BIM shifting from progressive first adopters to mainstream users,” says Mike Williams, PB’s CIO. “I think we are poised at the tipping point.”

BIM Challenges

Still, there are hurdles. First and foremost is transitioning building teams to use BIM.

“Getting people up to speed and training is number one,” Leff says.

Convincing people to use new technologies and change processes is another difficulty. “People are used to doing things a certain way,” Williams says. “Getting people to change is the biggest challenge.”

Many firms are using BIM champions, people who are passionate about the benefits of the process, to train staff and promote the use of the process within the organization.

Leff says he is starting to see people change their opinions about BIM. “Five years people did not want to deal with it,” he says. “Now you can see the attitude starting to turn around.”

On the software side, interoperability between the various packages is still a problem, Hellmann says. “Not all these programs talk to each other,” she adds.

The quality and type of information a software package exports to other systems also varies. Some packages, like Revit, permit information to be exported in a variety of formats. “The file format you choose will determine what data will be imported into another program,” Campbell says.

Industry groups such as the National Institute of Building Sciences and the International Alliance for Interoperability are developing standards governing the organization and format of data in the models along with a software neutral file format for transferring data between packages.

Managing all the data for a model is a huge undertaking and an evolving process, Campbell says. “We are just now figuring out how to manage all this data we are inundated with,” he adds.