Best of 2006 Awards
Hearst Tower Charts the Evolution of a Novel Design
BEST OF 2006: Project of the Year
One of the remarkable aspects of the 46-story Hearst Tower in Manhattan – the Best of 2006 Awards jury’s unanimous Project of the Year choice – is how much of the design was developed on the fly.
Many of the $500 million project’s notable features – from its striking “diagrid” structural system that creates four-story triangles on the façade to its status as New York City’s first gold-level Leadership in Energy and Environmental Design office tower – weren’t on the drawing board seven years ago.
Today, the 597-ft.-tall tower is the fruit of an open-minded design, said Michael Wurzel, a partner at London-based Foster and Partners, the project’s architect.
“The outcome was not pre-concluded,” he added. “It was an evolution.”
Along the way, the project hit many obstacles that define construction in Manhattan: the need to preserve a historic structure; building above and improving the subway system infrastructure; erecting a tower 4 ft. away from a neighboring skyscraper; and working at a busy intersection at 57th Street and 8th Avenue.
Today, the tower at 300 West 57th Street houses 2,000 Hearst employees who publish 16 of its signature magazines such as Cosmopolitan, Good Housekeeping, and O, The Oprah Magazine, as well as the headquarters for the company, which has nearly 200 magazine titles, 28 television stations, and 12 daily newspapers, including the San Francisco Chronicle. The 856,000-sq.-ft. structure consolidates employees from 12 locations.
It would have been much different had the company erected a new tower elsewhere, said Brian Schwagerl, Hearst’s director of corporate real estate and facilities planning. The notion of using the site of its 1928 headquarters was a table-setter.
“The city planning office and Landmarks Commission challenged us in 1999,” he added. “They said, ‘If you really want to have an overbuild on the site of this landmark structure, you can’t build a plain vanilla box. What is it that you can add to the New York City skyline?’”
A New Challenge from an Old Structure
Hearst first aimed for high-end architecture in its 1928 six-story headquarters. Though the building designed by Joseph Urban and George B. Post & Sons originally envisioned a larger tower above that was never built, its stature gained it New York City landmark status in 1988.
Schwagerl said Hearst sought expert help right away for its new project, tapping New York-based Tishman Speyer as development manager and San Francisco’s Gensler as master planner and later associate architect. It enlisted the architecture firm led by Pritzker Architecture Prize laureate Norman Foster, along with New York’s WSP Cantor Seinuk as structural engineer and Turner Construction of New York as construction manager.
As aspects of the tower took shape, Foster came to New York in September 2001 to present design documents to Hearst’s board of directors on Sept. 12. But the devastation wrought by the Sept. 11 terrorist attacks and the uncertainty it created led Hearst to hit the pause button on its own effort, Schwagerl said.
After four weeks of reassessment, the team decided to move ahead.
“We made the decision to proceed and to be the first skyscraper to be built in New York after the attacks,” he added.
The plan that took shape answered the city’s challenge of preservation and progress – keeping the limestone façade of the 40,000-sq.-ft. horseshoe-shaped landmark building, with its fluted columns and carved balustrades, but having the modern office tower rise within its footprint. It was nice in theory, but no small job, said Mark Pulsfort, Turner’s project executive.
“The big task was how we were going to demolish the old building and secure the landmark wall so that it was intact while the demolition occurred, then brace it as the tower went up, and eventually connect it all,” he said.
The team devised a multi-step process that started with staging in the original building’s interior courtyard and demolishing parts of the old U-shaped structure in order to install temporary shoring for the façade, Pulsfort said. The shoring consisted of a vertical truss system that supported the exterior wall at three points, acting as a horizontal diaphragm to spread out windload forces.
With shoring in place, the team proceeded with bulk demolition of the old interiors, leaving a 60-ft. perimeter around the façade. Interspaced with that effort, in places cleared out by demolition, the team began to build the foundation and install new structural steel columns.
Pulsfort said that as crews installed the permanent columns, they also tied them back into the old exterior walls, allowing removal of the temporary shoring and eventual demolition of the rest of the floor slabs, leaving only the braced façade.
Simultaneously, the team was mobilizing to restore the façade with sculptors and crafts workers. The $3 million stonework restoration required sandblasting away decades of grime; raking out debris from joints; adding weatherproofing; and restoring sculptures and exterior details. It also involved installing $2 million in blast-proof windows and setting 35,000 sq. ft. of plaster along three interior walls of the lobby and atrium.
Crafting a Robust Triangular System
The shoring and restoration work was technically challenging, but not as pioneering as developing the first tower in the Americas with a diagrid frame structural system for the entire building.
The diagrid’s inspiration came from a large, mundane fact: The site, which takes up the entire corner of Eighth Avenue between 56th and 57th streets, abuts the Sheffield, a 505-ft.-tall residential tower, on the west. The design team wanted to depart from the typical office tower layout that places stairs, utilities, and elevators in a central core to instead have this infrastructure back up against the other building, which otherwise would block window views, said Ahmad Rahimian, president of WSP Cantor Seinuk.
“But when you push the core against the west side, you have created an eccentricity in the structure – a side inherently stiffer than the east side,” he added. “In order to balance that, we suggested to the architect to look into some bracings around the Eighth Avenue side.”
The engineers devised various options, such as tightly spaced moment frames with exterior columns 20 ft. apart, partial diagrids, and a full diagrid design for the entire exterior of the structure. As the options came into focus, the diagrid’s benefits began to shine, said Foster’s Wurzel.
“We decided to go with the diagrid because it uses less steel and allowed us to
achieve 40-ft. spans,” he said.
The architects also recognized the environmental benefits of using 10,480 tons of structural steel – 2,000 fewer, or 20 percent less, than a moment frame. The geometric strength of the triangle shape also made the structure stronger, helping it efficiently handle seismic, wind, and gravity loads, Rahimian said.
But choosing the rarely used structural concept was only a first step, because it required a highly customized design. “At the concept stage, what decided whether it would work or not were the connections,” Rahimian said.
Typically, beams and columns come together at a gusset plate. But with the diagrid planned both as a structural support and aesthetic theme, a gusset plate holding four diagonal columns and two cross beams would have interrupted the triangular shapes with a large visual block.
“We had to develop a solution that was cost effective and constructible, without the nodes interrupting the expressions of the diagonals,” Rahimian said.
The result was making large custom-designed node structures in a shape that continues the triangular expression. All of the diagonal columns and horizontal beams essentially plug into the nodes, connected by bolts. The giant steel nodes weigh 6 tons for most connections and 9 tons at the corners, where eight columns and beams meet, Pulsfort said.
Erecting the frame required a high degree of precision.
“The erection tolerances were crucial because the structural pieces all interact,” Pulsfort said. “The location of the nodes had to be exact because of the X-Y-Z coordinates of the pieces. There were a lot of meetings on how it was going to all be put together within the schedule and cost.”
The diagrid creates alternating up-and-down, 54-ft.-high, four-story triangles on the exterior, starting at the 10th floor. The upper building is supported by concrete-reinforced 40-in. by 40-in. steel supercolumns and a 20-ton “keystone beam” in the base structure.
The diagrid’s lack of corner exterior columns also helped the designers create an eclectic feature of the tower – the “bird’s mouth” corners that slant inward and outward, Wurzel said.
“We realized that to avoid having rectangular floor plates stick out at the corners, we could cut back the slab at that point to create a dramatic angle,” he added. “The best view of a New York City building – or from it – is a diagonal view.”
While the glass curtain wall appears to run the length of each triangle, it actually is a standard system connected at each floor using mullions.
The construction effort also involved $8 million in improvements to the Columbus Circle subway station for New York City Transit, including new elevators, stairways, and an entrance.
LEED and a Good Housekeeping Seal
Hearst’s tower opened over the summer to become the first office building in the city to achieve a LEED gold rating for both core and shell and the interior fit-out. The achievement is notable because building green was hardly common when the tower was in design, Hearst’s Schwagerl said.
“So many people told us we don’t build green in New York City,” he added. “We had to go out of the box and look at European and California architecture.”
Applying green design to a high-rise was the main hurdle, said Bruce Phillips, managing director for Tishman Speyer, whose firm applied a scorecard to constantly evaluate achievable LEED points while adding building systems that would result in health and environmental benefits for the future office workers.
“We chose what we thought were appropriate increments to get value, such as improved indoor air quality, but also earn points,” he added. “They really broke some ground and did it in high style.” The team increasingly embraced the green concept as the project progressed, said Peter Han, a Foster associate.
“We took the environmental approach not just for the core and shell but also into the interiors,” he said.
One signature green feature, the $8 million, two-story lobby sculpture dubbed “Icefall,” evolved from a challenge to the design team to “excite us,” Schwagerl said. It has diagonal escalators, which link the street entrance to a mezzanine space, slicing through a cascading “waterfall,” using rainwater collected from the roof.
The runoff, which is chilled, also serves to cool the atrium in summer and humidify it in winter.
The team also gained LEED points by choosing exterior glass with a “low-E” coating to filter in natural light without heat-causing radiation; light sensors regulating artificial light use; high-efficiency HVAC systems helping the tower use 26 percent less energy than a standard building; a system that harvests rainwater in a 14,000-gallon basement tank to irrigate plantings, resupply the HVAC system, and reduce stormwater flow to city sewers; and environmentally friendly furniture, paint, and other finishes.
Other notable interior features – such as column-free floor spaces and the ability to create a grand multistory lobby and expansive skylit atrium – grew from the flexibility that the diagrid structure allowed, Wurzel said. While most floors house the magazine groups, others feature a broadcast studio; a fitness center; high-end conference spaces with triple-height ceilings; a 168- seat theater; and the high-tech kitchens and product-testing facilities of the Good Housekeeping Research Institute.
Schwagerl said while Hearst isn’t planning on building again for another lifetime, he hopes that the tower provides a blueprint for setting high design goals.
“It’s not that hard,” he added. “I have never built a skyscraper before, but New York City is just rich with great minds in real estate, architecture, and construction. We got the best out of them.”
Developer: Hearst Corp.
Architect: Foster and Partners; Adamson Associates; Gensler
Construction Manager: Turner Construction
Structural Engineer: WSP Cantor Seinuk
Development Manager: Tishman Speyer
Steel Contractor: Cives Steel
Mechanical Engineer: Flack + Kurtz
Geotechnical: Langan Engineering
LEED: Steven Winter Associates
Drywall-Plaster: Component Systems
Electric: Fred Gellar Electric
Plumbing: Almar Plumbing & Heating
HVAC: Center Sheet Metal
Lighting: George Sexton Associates