Issue 4 of 2014
DBIA’s 2014 Project of the Year, the Denver Union Station Transit Improvements Project, transformed 20 acres of blighted former rail yards into the vibrant centerpiece of a bustling downtown Denver, adding an iconic, eight-track commuter rail train hall, new light rail station and an airy, airport-like underground bus concourse. This public-private partnership spanned 20 acres and seven city blocks, making it the largest multimodal project to seek LEED® Silver certification from the U.S. Green Building Council. The finished station has the capacity to support more than 14 times the number of current daily trips taken to accommodate a rapidly-growing population and economy, and is now a tourist destination in its own right thanks to the team’s bold vision.
Organizing Multiple Partners
The massive redevelopment was done in phases, but the key component — construction of the transit elements in the station’s former rail yard — was just completed in February 2014, two months ahead of schedule (despite a later than expected start date) thanks to design-build project delivery.
“The project included construction of light rail, an underground bus concourse, a commuter rail train hall and the public spaces connecting them all,” explained Hunter Sydnor, public information manager for Kiewit, the company that led the design-build team. “When the project was first developed, it was through a ‘Master Developer Team,’ which included public and private funding sources. Design-build was used so that the project had flexibility for changing economic and environmental conditions and changing client needs.”
Distinguishing the project/team as Project of the Year came down to a remarkable ability to maintain open communication with so many stakeholders on such a large project — at $374.8 million, it was the largest transportation project underway in the United States. Sydnor explained, “Denver Union Station Project Authority (DUSPA) is made up of the City and County of Denver, the Regional Transportation District, the Denver Regional Council of Governments, Colorado Department of Transportation and the Denver Union Station Metropolitan District (the private partner). Clearly, there are many organizations involved with different needs, and the partnership developed between the organizations with a clear goal made the project successful and was key to getting the financing for the project.”
At 30 percent design development, the owner created the Kiewit Design-Build Team when they chose Kiewit under a separate contract as the Design-Build Contractor, with AECOM and SOM as the design partners. Design continued for nearly three years, reaching completion approximately one year after construction began.
To maintain alignment between design and construction, Kiewit coordinated the release of early design packages of the light rail station and underground bus concourse with AECOM and SOM. The Kiewit Design-Build Team met regularly to ensure that the most recent design schedule was fully integrated with the construction schedule. Conflicts related to the released design package were addressed well in advance of the start of construction.
Environmental Challenges
Due to the site’s former life as a rail yard servicing coal-fired trains, several environmental challenges related to contamination of the soil and water had to be addressed immediately. This complicated a different challenge related to the underground bus concourse, which sits just below the water table. “During initial stages of the project, we knew the water table was there,” Sydnor explained. “The issue was really how to design and build to accommodate it. Through the design-build process, we chose an alternative foundation that allowed us to reduce the amount of deep foundation that would take us further below the water table, thus we were able to build the bus terminal faster and more cost effectively.”
The team excavated more than 360,000 cubic yards of soil — enough to fill a 20,000-capacity sports arena over nine times — and over 270,000,000 gallons of water — enough to fill an Olympic-size swimming pool over 400 times — before pouring the four-foot-thick foundation.
Employing Best Practices
The entire project team, including the owner and sub-contractors, followed many DBIA best practices during the course of the project. Two DBIA Certified professionals served as liaisons and performed design coordination with Kiewit and its partners in order to create a project team that was truly integrated; embedding the lead architects and engineers in the contractors’ offices and holding weekly owner/architect/contractor meetings to ensure key decision-makers were frequently consulted.
Additionally, a Discipline Task Force was assembled, comprised of representatives from each of the design and construction teams responsible for a specific scope of work. The task forces met weekly to discuss issues for current and upcoming activities. Meetings were designed to build consensus on the best path forward based on design, constructability, execution, schedule and cost impact.
Since design continued a year after groundbreaking, the Kiewit Design-Build Team developed a phased approach in which design packages were released in alignment with construction activities. They sought constructability reviews and comment resolution on all design packages at 30 percent, 60 percent and 90 percent completion. Having AECOM and SOM in the main project office made this easier, as they were able to provide real-time resolution of design questions or concerns.
Controlling Costs
The Kiewit Design-Build Team collaborated to perform value engineering on the project, identifying design alternatives that saved costs while adhering to the intent of the design. For example, at 30% design, the team realized that in order to include moving walkways through the center of the pedestrian section of the Underground Bus Concourse, they’d have to be single file in both directions. The team worried this would be impractical and could create more logjams from passengers with children and luggage, so it was determined to remove them. This owner-accepted change order resulted in a savings of more than $1.3 million.
BIM also allowed the team to design a structure for buses to flow through that could avoid excessive ventilation by including an open-air roof. The ability to step back and look at the larger structure in a 3D model also ensured an extremely neat and orderly mechanical/electrical/plumbing layout, saving time and money through early and reliable communication with MEP subcontractors.
The Finished Product
Throughout the master planning and design phases, public meetings were held, primarily led by SOM and landscape architect, Hargreaves Associates. The meetings gave the community the opportunity to engage in the design in a meaningful way, with direct access to the design team. The meetings fostered support for the design and excitement about the project’s influence on creating a sustainable, thriving downtown core.
That excitement is now coming to life as development continues behind the original Denver Union Station, including the construction of office buildings, apartment complexes, restaurants and public plazas.
“The Denver Union Station Transit Improvement Project was exciting to work on with the iconic structures that are now part of the Denver skyline,” Sydnor added. “It has spurred new development and helped continue the revitalization and growth of the whole Lower Downtown area.”
“[Denver Union Station] is going to be flexible enough to transform itself over the decades as technology changes,” said Don Hunt, executive director of the Colorado Department of Transportation. That will come in handy, as many economic and real estate forecasts project continued growth for the Denver metropolitan area, which now numbers around 2.6 million people.
Denver City Councilmember Judy Montero described the entire Denver Union Station Project as, “a phenomenal example of a regional partnership.” The transit improvements led by Kiewit, AECOM and SOM has been a phenomenal partnership as well, and that’s why it is our 2014 Design-Build Project of the Year.