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The 52-story tower will have large amounts of exposed steel elements supporting an innovative curtain wall, requiring an intensive fabrication and installation effort.
With its shimmering skin of high-quality clear glass and ceramic rods that will appear to change color as light hits from different angles, the 1.6-million-sq.-ft. New York Times building has a chance to become an icon of New York City's skyline.
But one of the 52-story building's most striking aspects, already evident at the construction site, is the amount of exposed steel and how the team is accounting for the effect of the elements and the appearance of the final product.
"There is nothing in this building that is not deliberate," said Hussein Ali-Khan, vice president of real estate development for the New York Times.
The New York Times Co. will occupy the second through 29th floors - housing all of its New York-based employees under one roof for the first time - while the upper floors, with more than 700,000 sq. ft. of commercial office space, belongs to the Forest City Ratner Cos. of Brooklyn and ING Partnership, which are seeking tenants for the property opposite the Port Authority Bus Terminal on 8th Avenue in Midtown Manhattan.
The occupants will probably never know the level of precision that the $850 million building's design is requiring for steel erection. Even basic elements such as steel connections became complicated on the portions exposed on the exterior, said Tom Scarangello, project manager at New York-based Thornton Tomasetti, the structural engineer on the project.
"Normally, when you're working out connection details, you're dealing with things like clearances, but in the end of the day they're going to stick some fireproofing and sheetrock on it, and no one's ever going to see it," he said. "No one cares whether the bolts face this or that way, nobody cares how thick the plate is, nobody cares what wall stage you use. But here, both architects were knee-deep, with us saying 'Which way do we want the bolts to face, and do we want a hex-head bolt or a button-head bolt©' We got this stuff detailed out to the point that the iron worker knows which way the bolt goes."
The architects on the project are Pritzker-prize winning Italian designer Renzo Piano and New York-based Fox & Fowle, who created a design that "defies gravity" and presents an image of lightness and transparency. The design for a cruciform tower covered in steel, glass, and ceramic rods also has a base extending eastward that will house one floor of retail, a ground-floor public garden, and an auditorium, with the top three floors of that section housing the paper's newsroom.
The amount of exposed steel elements gave rise to the first technical dilemma: on a building this tall, the steel supporting the façade "grows" with the weather change in the seasons, with the total variation adding up to a floor-cracking four inches. Thornton Tomasetti came up with a system of lateral braces and outriggers that connect the exposed steel to the internal columns and essentially pins the outside steel to the interior.
The exposed steel also required the use of a special fireproofing paint and the significant detailing on each piece that would be visible from the outside. That process was so unique in New York that Piano's team, led by Serge Drouin, stayed on site to make sure that each weld and bolt was made precisely to specifications.
Construction on the project also took some unexpected turns. The September 11th attacks delayed final designs, setting back the start of construction. When excavation finally started, the team made a surprise discovery in the bedrock.
"The initial borings showed that we were going to get 40-ton or 20-ton rock on site, which is very standard for this part of Midtown, and we would have ended up with spread footing for the tower," Thornton Tomasetti's Scarangello said. "But as the site was cleared and we were able to get more borings, it turned out there was a seam of weak rock going through and around the tower area, so we had to propose some alternates."
About a third of the tower columns are now on 22-in. drilled caissons.
Then other hurdles arose. Last year, the project's steel fabricator, Interstate Iron Works of Whitehouse, N.J., went out of business, with its owner blaming skyrocketing steel prices and a tight pre-negotiated contract. The departure forced the construction manager, New York-based AMEC Construction Management, to effectively enter a new field and become the steel supplier for the project.
Steel continued to present not only technical challenges, but logistical ones as well. Faced with an expiring contract, steel workers went on strike in late July, halting construction for days. Despite the delays, however, the building remains scheduled to open in early 2007.
In addition to the exposed steel, the concept of transparency and lightness is realized at several different levels.
On the top of the building, ceramic rods extend above the roof, partially hiding a 300-ft. mast that tapers from 8 ft. at the base to 8 in. at the top. The steel beams grow lighter toward the top as they support less weight. These details help to give a feeling of lightness; along with the building's unique curtain wall, popular in Europe but virtually unheard of on this side of the Atlantic.
Rather than the city's standard reflective or tinted windows, the curtain wall uses extremely transparent low-iron Starphire glass, fabricated by Viracon of Owatonna, Minn., and low-e VE-2M coating. This arrangement leaves the interior vulnerable to glare and heat gain, a problem the Times and its architects did not want to address with power-hungry air conditioning units.
To that end, the team came up with a twofold solution for the windows that covers the exterior with 185,000 ceramic tubes manufactured by Germany-based Haldenwangere. The tubes dissipate solar light before it enters the offices, while allowing the color of the building to change with the sky. Inside, sensor-controlled solar shades automatically adjust to various angles of the sun throughout the day and different seasons. The team built a 4,500-sq.-ft. mockup of the system and performed extensive testing in what Glenn Hughes, the paper's director of construction, calls a "pagan experiment," because it measured natural light from solstice to solstice using 100 real-time sensors.
While the owners decided not to pursue U.S. Green Building Council LEED certification, a process that requires additional overview and cost, the team realized several energy efficiencies.
Some were inherent in the paper's needs, such as keeping its time-sensitive operations running during power blackouts. The team will install an onsite 1.4 mW co-generation plant burning natural gas, with the byproduct heat recovered and converted to hot water. The curtain wall and lighting design provide additional energy efficiencies, along with an underfloor HVAC system on the Times-occupied floors. Forest City decided to leave its floor layout options to the tenant.
Instead of the usual overhead air distribution, Flack + Kurtz, the New York-based mechanical engineer on the project oversaw installation of the underfloor circulation system that saves energy by allowing cold air to rise on its own, concentrating the desired temperature in only the lower 60 percent of the space where it's needed. The fully adjustable floor ducts allow customization anywhere in each floor's 32,000-sq.ft. space.
"The unique aspect is that it will be the largest underfloor air distribution system in the city, and the first high-rise with underfloor air displacement ventilation," said David Cooper, managing director of Flack + Kurtz.
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