New York’s Tallest Residential Tower Is Frank Gehry ‘Demystified’

A 70-story, folded, creased and curved stainless-steel curtain wall on an 867-ft-tall apartment building has been called “Gehry only on the outside,” as if the building is a fake Frank. It’s true that, when it opens next year, New York City’s tallest residential tower won’t be an internationally acclaimed cultural icon, as is the architect’s now-12-year-old Guggenheim Museum Bilbao in Spain. The 76-story high-rise is not as colorful, whimsical and structurally innovative as the nearly decade-old Experience Music Project rock ’n’ roll museum in Seattle. The new tower is not as description-defying inside and out as the six-year-old Walt Disney Concert Hall in Los Angeles. But that building was torturous to build: There were 10,000-plus requests for information (RFIs), and it was $174 million over budget and the subject of a dispute that ended in a $17.8-million settlement.

Draping Lower Manhattan’s Beekman Tower, Frank Gehry’s creases may only be skin-deep, but the depth of the building team’s accomplishment—producing a budget-driven, speculative apartment tower with the signature of the “king of swoopy” all over it—is not superficial.

The job, topped out and clad to the 51st floor, is under budget and on schedule, discounting a three-month work hiatus related to the Great Recession, says the local developer, Forest City Ratner Cos. FCRC says there are no claims to date and only 100-plus RFIs on the entire job, including the seven-faced, 319,000- sq-ft drape on all but the south face—hands down, the architect’s most ambitious facade ever.

This project is “Frank Gehry demystified,” says Joseph A. Rechichi, an FCRC senior vice president.

Bruce Ratner, FCRC’s chairman, had a Gehry “sculpitecture” in mind from day one. But he also wanted an economical and constructible Gehry, with minimal process pain. Initially, “we were concerned about [the curtain wall’s] constructibility, and long-term use,” Rechichi says.

The facade’s success relied on several strategies. One was the development of a traditional unitized curtain-wall system for the wall’s air-and-water barrier, with an outer rain screen for the wild shapes. Unitized systems are unusual for residential towers, especially rental ones. “For the size and scale of the project,” however, it had to have a unitized system, says John Bowers, Gehry’s project manager.

Unlike a stick-built system with costly field labor, a unitized system is shop-fabricated. Workers can install finished units quickly, without expensive staging.

On Beekman Tower, a floor plate can be completely enclosed in four to five consecutive working days, says Bowers. “The greatest advantage of a unitized wall system is in the schedule,” he says.

“Our ability to divorce the wall from the balance of the building was huge,” adds FCRC’s Rechichi.

A key move on FCRC’s part was to engage the curtain-wall supplier early under a design-assist contract. Another key factor was the use of sophisticated digital tools, including building information modeling (BIM) and computer-numerically controlled (CNC) cutting tools. Automation has “enabled me to bring buildings of architectural quality to fruition,” says the Los Angeles-based Gehry.

FCRC also used veterans of Gehry’s past projects for the facade and the reinforced-concrete superstructure. Curtain- wall supplier Permasteelisa North America (PNA) worked on the Disney concert hall and Manhattan’s 10-story Interactive Corp. headquarters—Gehry’s only other unitized curtain wall. Concrete contractor Sorbara Construction Corp., Lynbrook, N.Y., built Interactive.

The 1.1-million-sq-ft Beekman is a mixed-use development with a sculptural tower—a fat “T” in plan—that will...

...contain 903 market-rate units. The tower sits on a 100-ft-tall, six-story rectilinear podium, clad in masonry. The podium has a public school, the city’s first on private land, as well as an ambulatory care center for New York Downtown Hospital, which owns the land.

FCRC declines to reveal contract values and construction costs, except to say it closed on $680 million in bonds for the tower in March 2008. This total includes $204 million from the New York Liberty Bond Program, issued by the New York Housing Development Corp. The National Electrical Benefit Fund, FCRC’s equity partner, also provided a loan.

Gehry’s starting point for the facade’s design was the residential bay window, which lets “you step outside the [flat] facade, as if you were walking on air,” he says.

Gehry wanted a sense of movement—enter the folds, creases and curves connecting the pointed bay windows. “I’ve been playing with this issue of folds for years,” he says. He finds fabric folds primitive and comforting. “They humanize the building,” he says. For the Beekman facade, “I told my guys I wanted Bernini folds,” which have a harder edge, “not Michelangelo folds,” which are softer.

Gehry Architects New York PC started conceptual design in late 2003. From 2004-05, the architect explored 50 or so schemes, applying the geometry to the wall surface using 1⁄16-in.-scale physical models. In late 2005, when the scheme had been honed to stainless steel with punched windows, Gehry started building 1⁄8-in. models. The architect also digitized the surface to create a BIM.

Also in 2005, FCRC issued a request for proposals to three curtain-wall suppliers for a design-assist contract based on Gehry’s scope and parameters. “We liked [PNA’s unitized] design and engineering, and they met our budget,” says Rechichi. Also, PNA was the only bidder familiar with CATIA—the sophisticated 3D model Gehry had used on Bilbao, Disney, EMP and other projects.

During the design-assist phase, PNA, with Gehry, developed a set of rules to turn the wall’s free-form shapes into something that could be mass-produced. The goal was to minimize the expense of a double curvature and maximize more economic, “rule-able” surfaces.

The phase, which included developing the entire panelization scheme and keeping the curvature within the budget, took more than two years. “You can’t do a job like this without design-assist,” says Michael Budd, executive vice president in PNA’s Mendota, Minn., office. Strong collaboration is needed to get to the required level of definition, he adds.

PNA used finite-element analysis to reduce the free-form shapes to single curves. Gehry refined the shapes, based on PNA rules, so that more than 90% of the surface has a single curvature. This was accomplished by slight segmentation at the panel joints, says Budd.

“We did the work zone by zone and face by face,” says Budd. “It was an iterative process,” adds Bowers.

The contract-document phase began in January 2007. Gehry developed the surfaces and the wire frame for the curtain-wall units in collaboration with PNA. The performance mock-up was completed and tested in early 2008.

PNA signed its $90-million contract and began detailed engineering in March 2008. Fabrication of the assemblies...

...began that fall. Panel installation started about a year ago and is scheduled to be topped out in September. “There is no appreciable cost premium for the ‘premium’ curtain wall,” says Rechichi.

In the end, of 10,911 rectangular panels for 427,734 sq ft of the eight-sided tower, there are only 1,888 repetitive units. There are 1,568 shaped column-cover units, 2,178 flat column-cover units and 5,177 shaped spandrel units with glass. The 9-ft, 10-in.-tall units vary 3.5 ft to 7.5 ft in width. All the glass is flat.

Each shaped unit is unique. Permasteelisa managed to cold-bend 70% of the panels, mechanically rolling only the tighter geometries. Cold-bending, which is the most economical method, curves the metal to its yield point.

The curtain wall is made up of two primary components: an inner wall and a rain-screen panel assembly. All panels have interlocking male-female mullions and a mating horizontal stack. They also have anchoring clips that attach conventionally to embeds in the segmented edge slabs.

The inner wall, made of insulated glass, insulation and aluminum unitized panels, forms the primary weather barrier. The units are planar on the interior surface and segmented to follow the superstructure’s profile. For the columns and spandrel areas, outer rain-screen assemblies are made of formed stainless-steel sheets attached to ribbed aluminum substructures.

Unique Transition Stacking

No tower floor plates are alike. A unit’s gutter may be offset in or out from the unit below by nearly 5 ft. PNA developed an assembly to let the stack joints between floors shift in plane from floor to floor. This transition stacking is “unique for a unitized system,” says Budd. PNA submitted traditional 2D shop drawings to Gehry, with dimensions for only profiles. “If you want to check dimensions, you have to overlay the 3D models,” says Budd.

PNA uses CATIA for surface design and SolidWorks software drives the CNC cutters. PNA wrote its own material- resources-planning software for Disney, refined it for Interactive and revised it again for Beekman. “We have improved our ability to track these assemblies in the production process,” says Budd.

PNA provided load and structural reactions of the skin to the structural engineer. “I had to create a structure that would be able to take care of all the horizontal activities, independent of the dancing facade,” says Silvian Marcus, CEO of local structural engineer WSP Cantor Seinuk. Once that was done, he was able to play with the facade, he says.

Tower accelerations are controlled through stiffness and weight rather than dampers. The structure consists of a central core, perimeter columns and reinforced-concrete outrigger walls that span between the core and perimeter shear wall at mechanical levels six, 38 and 76. The outriggers, which are 1.5 ft to 2 ft thick, spread loads to perimeter framing and transfer loads from one column line to another as the building broadens toward the base. “The school has larger spans, which meant transferring out 90% of the columns above,” says Marcus.

Slab edges are in different planes every floor, but columns stay in the same plane for about eight to 12 floors, as a way to simplify the formwork. At “change” levels, columns broaden, encompassing the column location above and below.

The strategy avoided sloping columns, which have more complicated and laborious formwork. “If I had sloped columns for 76 floors, I would have killed the job,” says Marcus. “It’s a spec building, so I had to maintain the construction rhythm.”

Foundation work began in October 2006; superstructure work began in April 2008. Construction so far has had a few hiccups unrelated to the curtain wall. When the building was at the third floor, word spread of an investigation into regional concrete testing giant Testwell Laboratories, which ultimately was convicted of racketeering stemming from allegations it filed fake test results on more than 80 buildings in the area. Testwell was testing Beekman concrete. Without Testwell’s knowledge, FCRC had another testing firm check cylinders and compare them to Testwell’s. “We had to be prudent,” says Marcus.

When the frame was at the 27th floor, FCRC replaced Testwell. The structure was almost finished when the city began requiring protocols for Testwell-tested concrete. “We took additional cores, tested them and did all the necessary calculations,” says Marcus. “We found the concrete was according to the original specs.”

A bigger hiccup was related to the crippling economy. Last March, FCRC stopped construction and considered capping the frame at 40 stories because of financing and marketability issues. In May, a decision was made to...

...restart work and take the building to its original planned height, thanks to a historic project-labor agreement between the Building Trades Employers’ Association of New York and the Building and Construction Trades Council of Greater New York. In it, several unions agreed to one-year wage freezes and benefit cuts while also agreeing to no strikes or work stoppages. In return, contractors cut wages and benefits for management and reduced their own profit margins. Project costs were reduced by 16% to 21%.

FCRC declines to provide too many specifics about its agreement. Permasteelisa is participating through a $5-per-hour wage cut, among other concessions.

A third hiccup happened on Jan. 25, when wind gusted up to 100 mph. Vertical perimeter safety netting, tied to horizontal safety cable, shredded up from the 44th floor. The cable apparently started oscillating, and the turnbuckles at the cable ends unwound and came loose, says Rechichi. Turnbuckles, netting and some 2-ft-square plywood pieces flew off.

Stronger Netting

There were no injuries, but the Dept. of Buildings (DOB) stopped work and issued two violations to construction manager Kreisler Borg Florman: one for failing to safeguard the site and the other for storing materials too close to the edge. Measures were taken, including installing stronger netting. The DOB rescinded the stop-work order in phases and fully lifted it on Feb. 5. Environmental Control Board hearings regarding any penalties are scheduled for May 20.

Superstructure construction, complicated by the heavily reinforced shear walls, the undulating curtain wall and the changing floor plates, went smoothly. “The Frank Gehry factor only comes into play on the perimeter,” says William Kell, Sorbara’s chief estimator. “It’s painful, it’s time-consuming, but all the planning is a little sugar for the medicine.”

For the curtain-wall units to fit, layout was critical for the 14,000 aluminum embeds, set on the total 50,000 ft of slab edges. Each embed is a 1-ft-square box, 4 in. deep. “Gehry situates the curtain wall and then locates the slab edge,” says Kell. It is typically the other way around, he adds.

Sorbara did a “phenomenal” job on slab edges and bay-window slab projections, which only have plus or minus 1 in. of tolerance, says Budd.

A year in advance of construction, FCRC gave Sorbara a set of schematics to price the job; Sorbara bid the job when documents were 50% complete. Kell did all the estimating and budgeting without BIM. “I can see 3D in my mind,” he says. “Our budget pretty much stayed in line with the estimates.”

Concrete work, which started in April 2008 and was finished last December, was also complicated by the height of the building and the stiffness of the outrigger walls, which are as tall as 26 ft at level 38. Over 50% of the formwork for the 12,000- to 5,000-psi concrete was vertical; the norm is 20%, says Kell. All forms were hand-set because the layout changed too much and because slab edges are segmented and protrude. The curtain wall, installed by PNA’s local sub Tower Installation LLC, is going more smoothly than anyone expected, says Budd.

Occupancy is likely to start in May 2011. Rents have not been set, but the area’s going rate for a new one-bedroom in a luxury building is $3,000 per month. Is FCRC concerned about the economy putting a damper on the demand for high-end rentals? Robert Sanna, an FCRC executive vice president, says, “Once you get through the risk of construction, you are in a good position. The frightening risk is almost behind us.”