Simplicity and speed with hybrid walls
When building castles in the sky, the first rule is: Give yourself ample window space from which to admire the view.
That’s just what the minds at the architecture firm Cetra/Ruddy Inc. on Broadway, New York, did when they designed The Orion, a 60-story glass tower of luxury condominiums in the Hell’s Kitchen area, just off of Times Square. The sixth largest residential high-rise in New York, the 649,000-square-foot, 550-unit building on West 42nd Street features breathtaking views of the Hudson River and Central Park. Even the lower floors boast living rooms with story-high windows that fill each apartment with sunlight, courtesy of a cascade of glimmering curtain wall.
In frenetic, heavily congested areas such as New York’s West Side, where labor rates are high and glaziers are under the gun to close off floors quickly, hanging curtain walls one panel at a time simply doesn’t cut it. That’s why Orion’s glazier, W&W Glass Systems Inc. in Nanuet, N.Y., did what a growing number of glass professionals around the country have done when tackling high-rises in big cities: they used a unitized curtain-wall system. Rather than using traditional window wall units, the company installed pre-fabricated curtain-wall modules that were a lite wide and a story tall.
“You can’t do a high-rise stick building these days,” says Mike Haber, W&W managing partner. “You just don’t have the time anymore.”
‘You can’t close a floor fast enough’
Completed in the spring of 2006, the $158 million Orion is the first condominium to be constructed in the West 40s in more than 10 years. The building at 350 W. 42nd St. was constructed by Bovis Lend Lease LMB Inc. in New York and features a mix of apartments, from studios to three-bedroom units, all with floor-to-ceiling windows.
“There have been so many articles written about how glass is the new white brick of our generation,” says John Cetra, architect principal at Cetra/Ruddy. “But I have to say that glass is offering us so many more possibilities for different kinds of expression, both in terms of the quality of the space inside and how it makes the rooms feel. It’s so much more expansive.”
For all of its distinct qualities, the Orion is only one of the latest buildings to employ a unitized curtain-wall system.
“The other method takes too long in this fast-paced world of New York City construction,” Haber says. “They’re able to pour concrete so fast these days, you just can’t close a floor fast enough.” The minute that the reshores—those temporary supports used to hold up a concrete structure until it can support itself—are removed, contractors “want curtain wall installed on that floor.”
For the Orion, W&W started with vision glass 1-inch clear insulating with a 46 percent Solarscreen Radiant Low-E coating, VRE1-46, on the No. 2 surface, supplied by Viracon Inc. of Owatonna, Minn. For the spandrels, 1-inch clear insulating glass was used with 46 percent Solarscreen Radiant Low-E coating on the No. 2 surface, and Viraspan Warm Gray Ceramic Frit, V933, on No. 4.
“Glare reduction was a big concern,” says Don McCann, Viracon architectural design manager. “On the flipside, you’re looking at some potential privacy issues.” The VRE1-46 coating, with its 43 percent light transmission, “gives residents some degree of privacy, but the interior reflectivity is relatively low, so they can still see out.”
Once fabricated, the glass was sent to Sota Glazing Inc. in Brampton, Ontario, to be incorporated into large, modular frames 4 feet to 5 feet wide and 10 feet to 12 feet tall using Sota’s Hybrid-Wall system. True to its name, the system hangs a large amount of glass at one time and features a capless external appearance like a unitized curtain-wall unit. However, it can be installed between floors like a window-wall system.
It also “gives you this broad range of materials to use and compose your exterior look with,” Cetra says. Designers used this versatility to give The Orion milky-white spandrels, parts with a mirrored-finish and metal panels, too.
The unitized curtain-wall system also incorporates silicone gaskets in place of the seal joints traditionally used between floor slabs and window-wall systems, Cetra points out. “For the Orion, which is a 60-story building facing significant wind loads, that’s really critical,” he says. “Developers and the design team also felt it was a tested wall that has high integrity in terms of water penetration. You put it up, bolt it in place, and you have a dry interior from the moment it goes in.”
Sota launched its Hybrid-Wall line nearly four years ago and is backlogged well into 2008, says Steve Charbonneau, Sota technical services manager. “We were able to foresee the condominium market going crazy as it has in the last several years,” he says. Its largest customers have projects in New York, Chicago and Boston. Sota has yet to crack the European market with Hybrid-Wall but has sold about $50 million worth of the window technology to date, he estimates.
Glaziers turn to Hybrid-Wall because they can hang more glass at one time and the units are preglazed at Sota’s factory in a controlled environment, compared with the more precarious conditions found in the field.
Though costs vary regionally, Hybrid-Wall costs about 5 percent to 10 percent more than window-wall systems, Charbonneau says.
The premiums paid for the unitized product are significantly offset by the reduction in field labor costs, Haber says. With window wall, “you’re going to pay to erect all the metal and to glaze the wall,” he says. “With the Hybrid system, we’re not duplicating our efforts, and the shop labor is much more cost efficient.”
Putting it together
Any time you’re raising a tower, regardless of the materials you use, “it takes a really close-knit group: the fabricator, the contractor and the installer,” Haber says. That’s even more important when unitized curtain wall is involved. Not only does the glazier have to arrange man-hoist time with the contractor, he or she also has to ensure that the fabricator and unitizer are working closely together to deliver the goods on time. A second company placed between the fabricator and the glazier means introducing another variable into the mix that could potentially complicate a building schedule.
However, after five Hybrid-Wall projects in New York and more than a million square feet of glass installed, W&W has encountered few problems and can only foresee the amount of unitized curtain wall it uses growing in the future, Haber says.
“It does put more of a strain on the fabricator for getting materials to the right place at the right time,” McCann says. For starters, it means that the fabricator’s product manager needs to work that much more closely with the glazing contractor.
On the Orion project, W&W sent Viracon a schedule outlining when the glass needed to be delivered to Sota. Once that was agreed upon, the fabricator gave the glazing contractor a deadline for delivering all the measurements for the project.
Once the glass was ready, Viracon shipped the pieces to Sota’s Ontario plant, where they were assembled into story-high modules and glazed. From there, they were packaged in crates and shipped to the construction site in flatbed trucks, Charbonneau says. For jobs that require smaller Hybrid-Wall pieces, the company packs them in individual cardboard packages and ships them by van.
Upon arrival, the modules were dropped into place using cranes and man hoists and locked in with silicone gaskets. The beauty of the Hybrid-Wall, Haber says, is that “we don’t have to come back and hang outside of the building with a scaffold to do all kinds of wet seals.”
Yet, how smoothly the process goes depends largely on how much time has gone into working out the details, Haber emphasizes. “Logistics are tough, especially on a high-rise tower where there may be only three or four hoist cars, and you may need them three or four days a week all day long,” he says. “That’s why you have to get there soon, before all the interior trades need those cars as well.”
With traditional window-wall systems, “you’ll just have bundles of aluminum in a truck and crates of glass,” Haber says. With Hybrid-Wall, “everything is mapped out precisely where we know exactly what panel is on what truck.”
At the end of the day, though, the unitized curtain-wall system is just one more tool to help the designers create their castles in the sky and tenants admire the view.