Diamond in the Rockies

Daniel Libeskind dreamed up something special for the expansion of the Denver Art Museum, but it took a skilled Building Team to turn his concept into a reality.
August 11, 2010

Dan Kohl already knows the burning question that most museumgoers will have on their mind when the much-anticipated expansion to the Denver Art Museum opens to the public on October 7.

“How do they hang art in this thing?”

Kohl, the museum's director of design, is charged with designing and coordinating the exhibits within the new five-story, titanium-clad building. It's not a simple task, given the unusual geometry provided by Berlin-based design architect Daniel Libeskind.

Daniel Libeskind’s crystal-like expansion to the Denver Art Museum is turning heads in the Mile High City. Scheduled to open October 7, the 146,000-sf, titanium-clad structure will become the new front door to the art museum complex. Its dramatic angular form is punctuated with a sharply cantilevered section that juts over 13th Avenue toward the museum’s fortress-like North Building, designed by Italian architect Gio Ponti 35 years ago. A 100-foot-long glass-and-steel footbridge connects the expansion to the North Building and a new 6,300-sf events pavilion. Photos: Jeff Goldberg; courtesy of the Denver Art Museum

“The building has certain honesty to it,” says Kohl. “If you see a wall that's sloping on the outside, when you go inside that wall is still sloping.”

That means very little artwork will actually hang on the building's interior walls. Kohl had to design special, nonstructural temporary walls for the exhibits.

“As an exhibit designer, typically you're given rectangular shapes to work with,” says Kohl. “In this case, I was given spaces that are far more dynamic, and it's been fun to work with.”

Kohl's exhibits play off the building's crystal-like form, cutting at sharp angles through the gallery spaces and leading patrons to the dead ends where the walls and ceiling come to a single point.

“When people step into the building for the first time, I think they're going to be overwhelmed—in a good way—with the architecture and how the art is presented,” says Kohl.

Libeskind's creation has been described by some in the architecture community as a series of metal shards, a geometric explosion of glass, and even a massive origami experiment. But the Polish-born architect says he was inspired by the “craggy cliffs” of the Rocky Mountains.

“The shape came to me as I flew over the city,” said Libeskind in his design statement. “I copied the shapes I saw out of my airplane window.”

Libeskind beat out Arata Isozaki and Thom Mayne in an early 2000 design competition for the commission to design the $70 million building, which will serve as the new doorway into the art museum complex. A 100-foot-long glass-and-steel footbridge on the second floor spans 13th Avenue, leading museumgoers to a new, 6,300-sf events pavilion and the museum's North Building, designed by Italian architect Gio Ponti 35 years ago.

The building is dedicated to Frederic C. Hamilton, chairman of the museum's board of trustees, who donated $20 million to its endowment. The expansion will add about 50% more exhibit space to the museum, including 40,000 sf of new galleries for the museum's 60,000-piece permanent collection, three special exhibition spaces totaling 20,000 sf for traveling art shows, art storage areas, a 280-seat auditorium, a café, and a 3,200-sf retail store.

Most of the construction is being financed by a voter-approved $62.5 million bond issue. The remainder was donated.

The challenge for Libeskind and the Building Team was adapting the unusual shape into a state-of-the-art, 146,000-sf museum.

For building engineers at Arup, that meant designing a cost-effective steel skeleton that could withstand the unusually high lateral forces that flow from the building's complex geometry.

“We're dealing with walls that are leaning outward, so they have a natural tendency, because of the gravity, to pull the building apart,” says Atila Zekioglu, PE, principal structural engineer in charge with Arup. Zekioglu likens the lateral loads that are created by the leaning walls to what would be seen in California's heaviest seismic regions, “except we're dealing with static forces.”

The angular form of the exterior façade stays true inside the museum. Sloping walls and ceilings in the gallery spaces gave the museum’s exhibit designer Dan Kohl plenty of inspiration. His exhibits play off of Daniel Libeskind’s architecture, cutting at sharp angles through the galleries (above) and leading patrons to the dead ends where the walls and ceiling come to a single point (top).

Arup's solution was to reinforce the composite concrete foundation slab with structural steel plates, and then tie all major structural columns back to the foundation.

“The floor is acting as a tension tie for the inclined walls,” says Zekioglu, who is based in Arup's Los Angeles office. “The steel beams help with tension and compression; they're almost acting as struts.”

Developing a connection strategy for the steel members was an equally daunting task, says Zekioglu. To create the unusual form of the building, a multitude of beams, columns, and diagonal steel members had to come together in a series of nodes. Because three, four, five, and sometimes six members had to come together, not all members would be equidistant from the center of the node. “The further the member is away from the center on the node, the more eccentricity there is in the movement,” says Zekioglu.

The strategy involved first determining the sequence in which the beams and columns would enter each node, and then calculating the connection load for each member. Arup selected a hybrid connection type that utilizes both welds and bolts to join steel members. The number of bolts used in each connection varied depending on the load condition. Of the thousands of connections in the structure, no two are identical in load, says Zekioglu.

Three-dimensional computer models played a vital role in coordinating the layout of the structural elements and mechanical ductwork. During the design phase, Zekioglu's team created a digital wire frame model of the structural elements. Arup's mechanical design team imported the information into its 3-D model of the mechanical system layout. With the two models working in sync, the mechanical engineers could navigate the ductwork through the maze of structural steel members, says Erin McConahey, PE, associate principal with Arup's mechanical engineering group in Los Angeles.

Using Arup's 3-D mechanical model, mechanical contractor U.S. Engineering, Loveland, Colo., input the vital design data for the ductwork directly into its sheet metal cutting machines. All ductwork was constructed in the factory and shipped to the job site for straightforward installation.

“The 3-D model was an invaluable tool, especially given the complexity of the project,” says McConahey. “Every hole where we had to take a duct through a beam was cut in the factory, and every one of them was in the proper place when the contractor installed the ducts.”

McConahey says the mechanical team received just 21 RFIs related to ductwork and structural physical coordination on the project. “On a project of this size and complexity, you might expect to see hundreds of RFIs using traditional design approaches,” says McConahey. “The lack of RFIs that we're getting tells us that the 3-D approach improved coordination from the start.”

Using the 3-D models created by Arup and other design team members, including local architect of record Davis Partnership, construction manager M.A. Mortensen built a 4-D model to coordinate the timing of all major facets of the job, including steel, concrete, ductwork, piping, fire sprinklers, crane locations, and shoring steel. The move helped the construction team visualize the construction sequencing and work out kinks early on.

Kohl and museum director Lewis Sharp worked closely with Libeskind from the beginning to ensure that the museum's program requirements coincided with the architect's design scheme.

“I think people imagine because his geometry is so artistic that he would be difficult to work with and have him understand the practical needs of the institution,” says Kohl. “It was actually the opposite. He completely understood and was quick to make changes to accommodate our needs.”

One such change involved reworking the form of the structure during the schematic design phase. Libeskind's initial design would have led patrons through a narrow hallway to access the museum's largest special exhibition gallery, the Anschutz Gallery, located on the second floor at the south end of the building.

Kohl and Sharp felt that a larger circulation path was required to handle the heavy foot traffic through the 11,000-sf gallery. But widening the hallway would have meant altering the form of the building. Where some architects might buck at that request, Kohl says Libeskind was quick to reshape and rethink the sculptural elements of the building to widen the entryway by about 10 feet.

Kohl says Libeskind was also very judicious about the use of daylight. Too much can be harmful to the delicate artwork within the gallery and public spaces—a notion that some architects look past, he says. “If you tour art museums, you'll see a lot of windows the architect provided that are boarded up or screened over,” says Kohl.

Libeskind concentrated most of the windows and skylights in the museum's 120-foot-high atrium. Daylight will flood the space, which features a grand staircase that winds along angled walls.

Museum officials are expecting big things from the expansion. More than a million people are expected to pass through its doors during the first year of operation—about double its current annual attendance.

The additional space will allow the institution to show off more of its vast collection, as well as host an array of traveling exhibits, which the North Building was not equipped to handle. The new facility has ample storage and freight elevator capacity, and other back-of-house functions to accommodate large traveling shows, which are often the largest draw for museums.

         
 

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