- SPECIAL REPORTS
- THE MAGAZINE
Thanks to BIM and the efforts of HNTB, the Denver International Airport Hotel and Transit Center project has overcome any turbulence and smoothed out rough edges. HNTB, program manager with Parsons for the project used BIM on the large-scale addition to the airport that met LEED Silver certification (environmental) standards. Design for the project was done by Gensler and their local partner, AMD.
The project, which started in 2009, is big. Plans include a 519-room hotel and a 23-mile rail line that connected to downtown Denver. The airport wanted the project done with BIM, and its use helped streamline workflows and helped HNTB’s collaboration with firms such as Parsons, Gensler, AECOM and construction firms Mortenson, Hunt and Saunders.
Using Autodesk software, including Revit, AutoCAD Civil 3D and BIM 360 Field, the team used the virtual model to assess all of the digital goals for the airport. HNTB used BIM for many purposes, from spatial coordination and design review to cost analysis and construction scheduling. Not only did BIM allow HNTB to centralize the redevelopment program with multiple partners, it also gave the airport a framework to use BIM throughout the facility for future projects. In fact, the airport insisted on using BIM, viewing it as an investment.
“They wanted as-builts that were tried and true,” said Eddy Krygiel, the director of design technology for HNTB. “They were tired of accidentally putting backhoes through gas lines because they didn’t have updated and accurate drawings. They wanted a way to maintain that data set on through the life of the facility. So ongoing facility management was a very critical thing for them.”
Woolpert, a civil engineering firm, performed extensive LiDAR scanning of the existing building, which HNTB used to create BIM models of the existing building. To avoid disrupting any airport operations, the team carefully scheduled the scanning. LiDAR scans in public places were done during normal business hours. But the team worked on back-of-house spaces offline, with a scanning team operating in the early morning hours, typically between 1-4 a.m. “But they were able to get everything scanned, get everything compiled and we were able to create a model of the existing conditions, basically help the design team kick off and give them a way to attach to the existing building,” Krygiel said.
From there, the team did an extensive BIM plan that outlined all of the digital process for the Denver International Airport. It showed how the design team was going to interact with the existing building model and the level of detail they would design. In addition, it included all of the metadata associated with the project, from air-handling units to pieces of wall. The process took more than 18 months, according to Krygiel.
The team put in a lot of effort on the human end, too. The team met with each individual stakeholder for all the departments in the airports in an effort to assess their needs and created a list of all of the components they needed in the project. Importantly, the team also evaluated what wasn’t needed in the project.
“We didn’t want to model extraneously and waste time for the airport,” Krygiel said. “We were trying to keep this effort contained while still giving Denver what they needed.”
HNTB faced several challenges. First, there were many different firms—and many different people—involved. More than 200 firms have worked on the project, according to Will Lineberry, a design/technology manager for HNTB. “Not everybody is up to speed with the current technologies,” Lineberry said. “That has certainly been one of the significant challenges.”
So the team made sure everyone was up to speed. In some cases, that meant additional training. Project leaders talked with more hesitant members to help the deal with the change in technology and get them on board.
“It was a lot of working with every single member of the design team, making sure they understood what the requirements were, that they were comfortable with it and they knew how to execute it,” Krygiel said. “And if they didn’t, we would go back and reassess and re-discuss until basically they got to the point where they were able to perform.”
Other challenges included the aggressive speed, the sheer scale of the project and making sure that the data linked back to the airport’s system for ongoing operation and maintenance. At times, the obstacles appeared daunting, but the team persevered.
“There are points in the projects as there are in every project where people stand up and pull out their hair and they say, ‘Oh my God, what have I gotten into? This was a mistake. We should have never done this,’” Krygiel said. “I think those are really good moments. Those are good moments to step back and say, ‘Did I make the right decision? Is the BIM the right call for this?’”
Each time, Krygiel said, the team tried to pull back and look at the bigger picture, which sometimes could be lost in the weeds. In the end, “the airport always said, ‘This is absolutely the thing we should be doing,’” Krygiel said. “And they charge forward again.”
Krygiel and Lineberry both said BIM offered many benefits, and they learned much from the project.
“I think from a management standpoint, one of the takeaways was how important organization is,” Krygiel said. “As frustrating as it is to do 18 months of groundwork before you even start designing a building, I think a lot of that really paid off because having everyone with the same level of expectations before the project for what’s going to get modeled, what’s not going to get modeled, has really helped the process. It cuts down a lot on frustration. Nobody wants to walk in with one understanding, realize they’ve gone down the wrong path, and then have to change.”
Stuart Williams, the South Terminal Redevelopment Program Manager at Denver International Airport, agreed. In a press release, Williams said BIM helped identify challenges and allowed the team to run the project more efficiently. It also improved communication and made for easier workflows.
“Design is wrapping up, construction is ongoing,” Lineberry said. “Our charge right now is to make sure that everything goes according to that detailed execution plan, bringing the construction team together with the design team.”
HNTB also has used BIM and Autodesk software for work on Chicago’s Wilson Station, a major transfer station on the Chicago Transit Authority Red Line. One of the main entrances to the station goes through the Gerber building, a 100-year-old structure listed in the National Register of Historic Places. For HNTB, challenges included maintaining the integrity of the historic building.
As with the Denver Airport project, HNTB started with a LiDAR scan. “We did a mobile scan down the track, both above and below the track so we could figure out all the existing conditions,” Krygiel said. “You have not only the track alignment and structure that you are going to tear down and replace.”
Most importantly, the Chicago Transit Authority wanted the rail line to remain operational throughout the project.
“They wanted as little downtime as possible and as little disruption,” Krygiel said. “One of the things we did with the model was take it in to 4D and we were able to sequence it so we could say what portions of the tracks were going to come down and what sequence and when so we could always maintain two lines, one in each direction at any point in time.”