Monday, September 15, 2014
Waterfall Skylight for Wilshire Grand Tower Survives Cost-cutting
Hunter Communications Original News Source:
The Los Angeles Times
Link to article:
Massive Skylight would be skyscraper's signature element, but at what cost?
Excerpt: "The design for the New Wilshire Grand featured a plaza, a high-rise tower and a secondary building, known as the podium, housing a restaurant, a pool and ballrooms.
Connecting the elements became the challenge.
One plan included an ambitious Guggenheim Museum-like rotunda. Another tried extending the tower's facade over to the podium. Neither worked.
Finally, in the winter of 2012, Martin hit upon a skylight, a sweep of glass that unified the space and created an atrium where guests entered the hotel.
Jow said the solution was elegant and dramatic — a eureka moment that thrilled the design team. Then reality struck.
Borland and Aspis had to protect the budget and started to question the complexity of the design.
Martin's early vision, rendered by computer, included convex and concave curves that required individual panels of glass to be custom-bent, an especially costly process.
Seismic tests also determined that the structure would have to move 15 inches — side to side between the tower and the podium — in the event of a major earthquake, and it would have to be restrained from lifting up in a windstorm. No one was certain if it could be engineered.
Then there was the question of how it would be cleaned. “ In the eyes of estimators and contractors, anything square is better. The fact that we had something lyrical and poetic in the design is a conflict in their minds. ” - Tammy Jow Share this quote
One design suggested two catwalks 3 feet wide for cleaning crews, but the structures encroached on the view. Another recommended trapdoors, but they detracted from the appearance.
As other costs on the project rose, the skylight became a target.
"In the eyes of estimators and contractors, anything square is better," Jow said. "The fact that we had something lyrical and poetic in the design is a conflict in their minds."
That's not the way Borland saw it.
"The difficulty is that the client has a vision for the project that isn't in keeping with the budget," he said. "And the design team always wants more."
The budget for the skylight was cut in half to $1.5 million, Jow said, and that was before cost estimates came in for the steel and its design: more than $5 million. And the custom glass panels would add more.
To ease tensions within the team, Jow deferred further discussion until she and the designers could answer the most persistent complaints.
She and designer Joseph Varholick traveled to Europe to learn about a process in glass design known as cold-bending. Instead of heating glass to shape it, fabricators contort the cold glass slightly, then snap it into frames that have been engineered to hold the shape.
Huddling at his computer, Varholick calculated that with 475 glass panels, the skylight would have the sweep and grandeur that Martin had called for. And each of the panels would be essentially flat, bending no more than three-quarters of an inch.
Varholick's work helped ensure that the glass would cost no more than $2 million.
Jow's team took its findings to the engineers and budget managers. The designers thought they were making headway, only to discover later that the skylight was still listed for elimination.
Martin tried to hold fast. The skylight was a defining stroke. Still, he grew so frustrated that he yanked the skylight from the plans.
As Jow explained, he was tired of being second-guessed by cost managers who 'would prefer to drop in a plaster, stucco box at the front door.'
'Any designer would be insulted,' she said.
Martin even presented an alternative: an open-air trellis much like the Lath Palace at the Botanical Building in San Diego's Balboa Park. But priced out, that idea saved no money.
So he took the issue to cousin Chris, who has the authority to set budget guidelines for the project. He knew it was a gamble, but the debate needed to be settled. Chris could either vote against the feature or make a concession.
Eventually Chris agreed that the skylight would remain but with one stipulation. With the glass already priced at $2 million, he insisted that the steel and its design cost no more than $5 million.
The design team then reconsidered the structural beams that supported the skylight. They curved as they followed the contour of the podium and tower.
After studying the elevations and cutaways, the designers realized that the beams would not need special fabrication to flow between the buildings.
The same effect could be achieved for less money with straight pieces, segmented to follow the curves of the structures.
The solution was a breakthrough. By Jow's estimate, it saved about $500,000 and ensured that the steel would come in under budget.
Shortly afterward, engineers were able to devise an attachment that allowed the skylight, fixed to the podium, to move on the tower side during an earthquake. And to support cleaning crews, they added ring hooks in the tower and made the glass thicker to withstand up to 300 pounds.
Last Tuesday, the project's engineers, architects and managers gathered for their weekly meeting.
Martin and Jow were eager to discuss the skylight. They had talked over the weekend and decided that they had found the least expensive and best solution. They wanted it approved.
And at last, it was — 21 months after Borland first saw the plan.
For $6.5 million, the New Wilshire Grand will have its river of glass."