Steel this Building
Cost, Time and Weather Lead Manhattan Residential Developers To Steel

By Tom Stabile

Carlton Brown saw poor soil conditions, a height limit and a tight budget for his planned eight-story mixed-use condos in Harlem and asked, "Why not steel?"

Brown, principal of Full Spectrum Building & Development, which is building 1400 Fifth Avenue, added, "The architect said, ‘Oh no, we never do steel for residential buildings in New York.’" Ultimately, steel won.

Brown said that steel led to a lighter building—800 tons of structural steel, —compensating for the soil issues, and created a flexible project schedule not hampered by the cold weather that makes concrete curing a hassle. It also paved the way for an exterior panel system that attached easily to the steel superstructure—saving both money and time on the 225,000-sq.-ft. project.

Similar rationales echo in steel residential buildings sprouting across Gotham.

Money is Time, Time is Money

Concrete still rules in most Manhattan residential projects, primarily because poured columns can create more compact floors than steel ones, allowing developers to squeeze more floors into buildings of the same height. That calculation might not translate into more floors, however, when height limits come into play.

For example, at 1400 Fifth Avenue, 4 in. more spaceper floor using concrete didn’t add up to a new floor under an 80-ft. height restriction.

"We were able to keep the base floor-to-floor height tight even with steel," Brown said.

Steel’s cost advantage is also an issue. Ken Haron, president of Artimus Construction, said the per-square-foot savings led him to choose steel for five residential buildings he is developing around Harlem, such as the 64-unit Rosa Parks Condominiums at St. Nicholas Avenue and 118th Street. Even with taller floors and fireproofing costs, Haron said it gave him a 30 to 35 percent savings over concrete.

"When we sit down to calculate which will be the cheapest way to build in today’s economy, the way to go is steel superstructure and concrete floors," Haron said.

Such calculations factor in higher costs of labor for concrete, said Trevor Salmon, a structural engineer who worked on the 1400 Fifth Avenue project. "Concrete is just not competitive," he added.

And then there’s the weather, said Ken Smuts, project executive for Jeffrey M. Brown Associates on The Porter House condominium project in Manhattan’s Meat Market district.

"The cost to do concrete in the wintertime—from the admixtures to prevent concrete freezing—is prohibitive," Smuts said.

An additional draw for steel is the chance to finish projects more quickly.

Haron said steel requires more upfront planning, including earlier contracting with suppliers, more shop drawings and the wait for fabrication. However, over the course of a project, steel can be faster, said Ray Dar, project manager with Flintlock Construction on an 11-story, 68-unit rental building rising at 756 Washington St. in Greenwich Village. Dar said steel saved at least two months on the job and allowed for smoother in-job adjustments.

"This was a fast-paced job," Dar added, noting that when the foundation work finished in frigid January, steel erection was a better option than concrete.

Steel isn’t faster in all respects. Laborers can pour a concrete floor in two days, depending on the footprint, but a steel floor level can take a week to bolt, tighten and check, said Robert Germano, project manager for HRH Construction, general contractor on 1400 Fifth Avenue.

However, steel can save on time in other ways. William Bastidas, general superintendent for HRH on the project, said the lighter steel structure required fewer piles, saving time on foundation work.

An additional time factor is contractor availability. Artimus Construction’s Haron said there are currently more steel contractors looking for work. Steel’s relative cost could change if fewer contractors were available.

"If you can’t find steel contractors who can start immediately and finish in three months, for example, and the concrete can come in and do it in a month, sometimes we’ll say, ‘Let’s bite the bullet,’" Haron said.

Design Considerations

Steel offers additional choices in terms of layout, façade materials and project planning.

For Jeffrey M. Brown Associates, the choice of steel for its Porter House project in Manhattan was a natural. Instead of razing a 98-year-old former wine warehouse, the firm decided to renovate the masonry structure and expand it.

Smuts said that in order to maximize the allowable building size, the firm built four new steel floors on top, while cantilevering a section that jutted eight ft. over an adjacent building. Using steel girders, columns, tubes and gusset plates, the cantilevering became an intricate but ultimately strategic move that allowed for expansive open living spaces.

Jeffrey Brown, principal of the firm, said steel was the wisest choice for tying the new structure into the cast-iron columns, steel girders and thick wood beams on the existing portion of the building. It also made it easier to form a complex tie-back system bringing the cantilevered load back to the core of the building and into minipiles driven into the bedrock.

The steel superstructure also complemented a temporary steel-shoring structure that allowed the project team to relocate core columns during initial phases.

"The steel let us weave a new structural frame through a 98-year-old building," Jeffrey Brown said.

Steel offers ample flexibility in flooring choices. At 756 Washington, Flintlock’s Dar said the developer chose 8-in. precast concrete floors that fit into the girder-column alignment. At 1400 Fifth Avenue, the choice was a 28-gauge corrugated metal deck atop 14-gauge metal joists with 4 in. of concrete poured as the flooring, offering a lighter option.

Additional flexibility from steel comes in the choice of building skin, said Jumaane Stewart, an architect on 1400 Fifth Avenue for Roberta Washington Architects. Steel allowed the developer to choose prefabricated panels of brick and synthetic stucco designed by Eastern Wall Systems. Those were welded onto the steel columns, a cheaper option in terms of materials and labor.

"You decrease your construction completion time," Stewart said. "The panels are made in the shop, and the erection is very quick."

Similarly, steel on the Porter House’s upper floors offered an easier system to connect the complex zinc panel system designed by Jonathan Mallie of SHoP/Sharples Holden Pasquarelli Architecture.

Steel also allows for masonry exterior, as is the case for Artimus Construction’s projects and the 756 Washington job. For the latter, Dar said the masonry ties through a waterproof wall into light-gauge framing that connects to the steel superstructure.

Carlton Brown had one other reason to choose steel. It will help him gain U.S. Green Building Council LEED certification for 1400 Fifth Avenue, thanks to structural steel that was up to 70 to 80 percent recycled.

And now, he’s hooked.

"We have two other projects on the board, both residential," he added. "They will both be steel buildings."