The $80-million rehabilitation of Building 77 at the Brooklyn Navy Yard will include cutting through the 6 in. thick reinforced-concrete walls to install windows on some of the higher floors, making the structure more suitable for office space. © John Bartlestone
Building 77, a massive concrete structure at New York City’s Brooklyn Navy Yard that once held provisions and ammunition for warships, is slated for an $80-million rehabilitation.
April 9, 2013—The Brooklyn Navy Yard Development Corporation (BNYDC) began preliminary work recently on an $80-million rehabilitation of Building 77, an imposing 18-story concrete monolith at New York City’s Brooklyn Navy Yard that was built in just five months in the summer and fall of 1941, just before the United States entered World War II.
“They were completing roughly a floor a week at the peak,” says John Coburn, RA, LEED AP, the principal architect for the BNYDC. “This is a one-million-square-foot building. That’s sixty thousand square feet a week of reinforced concrete, the columns, and the floors. It’s pretty incredible.”
There are no windows in the lower 11 stories, which were used as warehouse space. Although the 12 ft tall, 18 ft wide reinforced-concrete wall panels covering the exterior of the building on those levels are nonstructural, they are 6 in. thick. The floors are equally robust. The ground level is rated at 1,000 psf. The upper levels are rated for progressively lighter loads ranging from 400 psf at level 2 to 150 psf at level 11.
The building was probably used to store ammunition for warships, but there is little written history of the structure to corroborate that, Coburn says. “It’s a question, why would [the navy] build a warehouse with six-inch-thick concrete walls? They had a lot of other storage space that wasn’t built that way.”
What isn’t in question is the use of floors 12 through 16, which housed office space for such high-ranking officials as the yard’s commandant. Above that, two mechanical floors hold a large air-conditioning system and radio equipment once used to communicate with the fleet.
“The story I’ve heard repeated most often is that this was originally going to be a concrete box warehouse for munitions storage,” Coburn says. “But there was concern that it was unsafe to store munitions so close to the perimeter of the yard. And in order to prove it was safe, the navy added these office floors on top to say, ‘It’s going to be so safe [that] we’re going to sit on top of it.’ ”
Although the building has been largely unused for many years, the robust concrete structural elements are perfectly sound. Rehabilitation efforts will focus on the electrical, mechanical, and plumbing systems in the structure, which are original.
“The roof and windows weren’t maintained,” Coburn says. “Right now, if you were to walk into the building, the upper several floors have standing water from roof leaks that have gone on for years and years.”
The existing roof is built upon a concrete slab that is still structurally sound, Coburn says. After minor surface repairs, a high-performance single-ply membrane roof will be installed.
The BNYDC plans to replace the single-pane, steel-framed windows with double-pane, aluminum-framed versions, which will be more efficient. However, the mullion dimensions and spacing of the new windows will mimic those of the original units.
The BNYDC also plans to add windows to floors 9, 10, and 11, opening those stories to a greater variety of uses. This presents a construction challenge on the project, as workers will have to cut through the thick, reinforced-concrete panels. The replacement panels and windows will be carefully designed to complement the original building fabric.
“The panels are nonstructural, but they are massive,” Coburn says. “We are talking about one hundred feet off the ground, cutting out these concrete panels. Then we have to replace them with new, precast-concrete panels. We will have spandrels of precast concrete and then new windows.”
Another challenge will be removing the 1941 air-conditioning equipment, a system designed to cool 300,000 sq ft of office space. The equipment was installed on the 17th floor and was probably lowered into place as the building was constructed. The 17th floor isn’t serviced by any of the buildings freight or passenger elevators; access is via ladders.
“All of that equipment is well beyond being repairable. The contractor is going to go through some gymnastics to torch everything apart and get everything out,” Coburn says, explaining that large chutes within the building will be used to bring the pieces down.
Coburn says the rehabilitation is being carried out because of the high demand for floor space at the Brooklyn Navy Yard. Shiel Medical Laboratory, which currently occupies space in another building there, plans to move into Building 77 at the completion of the 21-month project. The company has secured an additional 180,000 sq ft to lease to other companies in the field, the Wall Street Journal reports.