Famous limestone to grace 15 Central Park West.

If you've seen architectural renderings of 15 Central Park West, maybe you've thought that there's something strangely familiar to the look of the new 550-foot luxury residential tower. For a clue as to what that is, try looking a bit higher in the skyline. The Indiana Limestone to be used for 15 Central Park West is from the same quarry and vein as the limestone used for the Empire State Building.

Developer Zeckendorf, LLC, and the project's architect, Robert A.M. Stern Architects, chose Indiana Limestone for their ultra-luxury residential project, where apartments are reportedly going $300 psf.

"The most elegant buildings on Central Park West have limestone," said Michael Jones, an associate and project architect for 15 Central Park West at Robert A.M. Stern Architects. Jones also noted that Indiana Limestone will help distinguish 15 Central Park West from the glass-and-steel

buildings in the area and tie-in with many other buildings on Central Park West.

"For a building of this location and importance, stone was the most appropriate solution and Indiana Limestone was the most appropriate stone," a spokeswoman for the developer said.

She added that Indiana Limestone, which has a range of tones from buff to grey, is both beautiful and durable and has a compressive strength greater than any other limestone.

According to Duffe Elkins, director of sales for the Indiana Limestone Company of Oolitic, Indiana, the limestone for 15 Central Park West is coming from the Empire Quarry from a deposit just a few hundred yards away from where the same Indiana Limestone was quarried for use on the Empire State Building, which recently celebrated its 75th anniversary.

Elkins said more than 7,500 tons of the raw material will be needed for 15 Central Park West. He called the limestone from the Empire Quarry "unique" because of its "full-color blend is complimentary to other building materials."

This deposit's full-color blend, he explained, ranges from off-white to bright grey. He added that it is a Class 2, medium density, ASTM-certified stone.

While Indiana Limestone can be manufactured in different ways, from panels to ornate shapes, it starts its journey for the Manhattan building at the quarry deposit.

There, blocks of stone for 15 Central Park West will average eight feet long and four feet high and be from two-feet to three-feet deep.

After these blocks are cut, they are sawed into slabs, varying in thickness. Slab thicknesses will be based on what has to be manufactured, Elkins said.

For 15 Central Park West, the stone blacks will be cut into two-inch-thick panels. "these will feature a sawn finish on them," Elkins added.

After the panels are processes, they are loaded on to a palette, and then they are checked for quality and sent to Canada to be affixed to precast concrete backings. From Canada, they are shipped to the project site in New York or approval and then erection.

In all, 15 Central Park West will feature more than 85,000 panels covering 290,000 square feet on the building's facade. Each panel, with its precast concrete backing, will weigh from 6,000 pounds up to 20,000 pounds each. The limestone panels with the precast concrete backings will be erected beginning in February 2006 and take a year to complete.

In addition to the facade, Indiana Limestone is being used for the building's cornices and string course. String courses are one-foot tall and two-inches thick.

It is also being used for the pilasters; columns at the top of the building to help frame the skyline, for a two-story-high arch that will be open to the sky and visible from Central Park, on the east and west elevations; for balconies and balcony brackets, parapets, and at the base of the building's bay windows.

Construction of the building's concrete-framed superstructure will begin in August 2006 and construction is expected to be completed by June 2007. Once completed, Jones pointed out, 15 Central Park West will be "an icon added to the New York City skyline."