Bastille to Broadway

Building team rises to the challenge of constructing Hotel Sofitel New York in midtown Manhattan's dense urban environment
August 11, 2010

Bastille Day-July 14-is France's equivalent of Independence Day in the United States, named for the storming of a Paris prison by the French citizenry that sparked the French Revolution. The opening of the Hotel Sofitel New York on Bastille Day 2000 sparked a revolution of its own for owner France-based hospitality firm Accor. The hotel establishes the company's long-planned, initial property in New York City-the new flagship of nine existing U.S. properties-and sets a new standard of quality for the upscale chain in North America.

The project's completion also signified a victory for the design and construction team in overcoming the barriers to building a fast-track, high-rise hotel on a tight site in a historic section of midtown Manhattan.

In addition to Accor North America, the building team consisted of the New York City office of project manager Constructa Inc., New York City-based Brennan Beer Gorman Architects (BBG) and construction manager (CM) Bovis Lend Lease LMB Inc., New York City.

The 398-room hotel occupies a 15,800-sq.-ft., T-shaped lot, between 44th and 45th streets. The main tower section rises 31 stories and is flanked by two 20-story wings.

Making good neighbors

The hotel's prestigious neighbors along 44th Street's "club row" include the historic Harvard Club, New York City Bar Association and the famed Algonquin Hotel. Its most prominent neighbor, the landmark New York Yacht Club, is next door. The building team took measures to forge positive relationships with these distinguished neighbors.

Apart from simply being a good neighbor, it was necessary to demonstrate to the city's Landmarks Preservation Commission that precautions would be taken to protect the Yacht Club-a six-story limestone building constructed in 1898-during blasting and excavation for the hotel's two basement levels. While the hotel was under construction, scaffolding was erected to protect the club's Tiffany skylight, the only one of its kind in New York City that remains in its original location.

"We had to chop out rock up against the Yacht Club foundation," says Bill David, project executive and vice president of Bovis' hospitality group. "There were concerns about noise and vibrations." Rock anchors and underpinning also were required as part of the excavation.

The relationship of the hotel and Yacht Club became even closer with the purchase by Accor of the building's available air rights, which enabled the company to expand to 280,000 square feet of hotel.

Sofitel's new definition

"The permitting and working with the neighbors were expected," says Jack Wei, construction manager for Accor. "We were lucky in having a good neighbor in the Yacht Club. The difficulties on this project, contrary to what most might anticipate with building in midtown Manhattan, were more internal than external."

The main difficulty, according to Wei, was in defining the project. "The Sofitel that we were developing was actually a new generation of hotels designed specifically for North America," says Wei. This "new definition" involved elevating the chain's luxury status from a four-star to a four-and-a-half-star hotel and took place as the building was under design and construction. "We embarked on the design and construction before fully defining the project," says Wei.

"The project was on a fast track from the beginning," says Arthur Blee, director of development for Constructa, explaining why the company decided to use a CM format. A 1997 design competition led to the selection of BBG. A second design competition resulted in the selection of French-based Pierre-Yves Rochon as the project's interior designer. Rochon, who had designed interiors for Hotel Sofitel in Paris and London, brought a refined French sensibility to the project that Blee calls a contemporary art-deco feel. "It's comfortable and in a way it's a slightly clubby atmosphere," he says. Imported Italian slab marble is used to establish the hotel's luxurious atmosphere, along with millwork, domed ceilings and plaster moldings.

Despite many logistical and scheduling hurdles, "construction actually went fairly smoothly," says Blee. "We were always chasing the design. We poured floors on a two-day cycle. Everybody's obligation was to keep up."

A blend of base and tower

Architect BBG was challenged to design a building that blended with the tradition of the neighborhood yet established its own identity as a modern luxury hotel. To this end, the hotel's first four floors are clad in limestone to match the exterior of the Yacht Club and acknowledge the popularity of limestone as a building material in Paris.

Above the limestone base, the exterior transitions to modern materials-blue-tinted curtain wall and precast-concrete panels. "Accor wanted a contemporary statement, but at the same time a nod be given to the neighborhood," says Yann LeRoy, design partner for BBG. "So, we used limestone, which was a material used a lot in New York and Paris throughout the art-deco period of the '30s. It established a link between New York and Paris.

"Up above, on the 44th Street side of the tower, the façade is contemporary in character with a series of glass drums nestled in on one another. The gently curving curtain wall is framed in precast-concrete panels," says LeRoy.

LeRoy is particularly proud of the sill mullions that run through the punched windows on the building's two wings. The mullions separate the upper fixed window from its lower operable portion. On the wings' upper suite levels, the sill mullions wrap around corner windows and are an integral feature of the precast-concrete panels. "A lot of manufacturers tried to dissuade us from using them because more time is required to remove the panel from the form," says LeRoy. "But it lends a visual solidity to the building exterior that you probably wouldn't have with an aluminum mullion."

Acoustical control was the major thrust of the window design. The owner mandated European sound-transmission standards for the project. Guestrooms had to meet background noise levels equal to or less than 35 decibels (dBA) during the day and 30 dBA or less at night. "The noise-transmission requirements were far superior to anything I've seen in New York," says LeRoy. City standards are 5 dBA higher.

Noise reduction was accomplished by using a 13/8-in.-thick, double-glazed curtain wall, and punched windows surrounded by precast-concrete panels. The outboard lite glass consists of two panes of glass laminated together. Special tooling was required to maintain the extra air space between panes. The glazing specifications were a first for Texas-based glass supplier Guardian Glass.

Other room amenities dictated by the owner include high-speed Internet access, European-style ducted fresh-air supply for all guestrooms and a four-pipe, water-circulated heating and cooling system designed by M/E/P engineer Cosentini Associates, New York City.

Tight constraints, many mandates

Though the hotel extends through the 200-ft.- deep city block, it is narrow. Its 44th Street main entrance is a mere 40 feet wide while the 45th Street side is 120 feet wide. This tight footprint required the building team to maximize efficiency by devising ways to accommodate a larger-than-normal elevator bank, lounge bar, restaurant, exercise room, ballroom and conference rooms. Accordingly, blasting and excavation were required to accommodate two basement levels-health club, kitchen and laundry facilities on the first basement level and mechanical rooms on the second.

Entering the hotel from the 44th Street side, the narrow vertical bar of the "T," patrons are greeted with an open lobby and rotunda. To make the most of the area, the concierge is located off to the side of the main entrance. Rather than diminish the lobby's impact, the front desk is situated off of the rotunda near the elevators. A French bistro and bar lines the length of the 45th Street expanse.

To maximize glass area, the building core is located at the junction of the "T" plan. The elevator core houses four passenger elevators and three service cars; one side of the elevator core is designed to act as a shear wall.

Because of the hotel's tight asymmetrical "T" shape, accommodating lateral loads was a challenge for DeSimone Consulting Engineers, New York City. "You have to find a part of the structure that is able to take the stress from the wind," says Zoe Pappas, DeSimone structural engineer. Vincent DeSimone, the firm's CEO, selected a lateral load system based on shear walls. The east and west shear walls control torsion created by the hotel's shape.

As Accor required that the fourth-floor ballroom-as well as other areas on the hotel's first four floors-be column-free, some columns stopped at the third or fourth floor and some stopped or changed location below the third floor. Their loads were transferred through concrete mats, one of them being 25 feet square by 60 inches deep. The mats act as footings for the columns on the upper floors. "Because of its size," Pappas quipped, "when one of the mats was being formed, people mistook the transfer beam for a swimming pool."

To preserve the view from the rooms on the 44th Street side of the building-which feature the curved curtain wall-a cantilevered slab with special reinforcing was designed. This permitted a single column to be used at the perimeter of each room.

Atop the reinforced concrete superstructure, the building is topped off by what the team calls the "top hat," a 26-ft.-diameter structural steel enclosure that slopes from 40 feet in back to 48 feet in front. This drum houses two water-filled cooling towers. Aluminum panels enclose the steel and a fiber-optic display on the exterior gives the illusion of geese in flight.

Timing of the essence

Conditions presented by the urban site and fast-track method made planning and scheduling crucial for the construction manager. Carlos Pesant, senior vice president and officer-in-charge for Bovis, credits the company's early involvement for giving it a leg up on the project. "We were engaged a year before we started construction to provide all the preconstruction and design management," he says, noting that Bovis had a cost-plus contractual arrangement.

"Because of the uniqueness of the superstructure, we were only able to place one crane on site," says Bovis' David. This required the superstructure erector and precast erector to share the crane. "The crane never sat idle," says David. To further the process, the precast fabrication and erection were split into two contracts to expedite engineering of the shop drawings.

Because the hotel was inserted between existing buildings, superstructure contractor Sorbara Contracting, New York City, spurred production by using sliding forms in the pouring of slabs.

In the end, the building team gained victory in its quest to bring a new kind of Hotel Sofitel to North America.

         
 

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