Office Penthouses Leasing Slowly in Midtown Tina Fineberg for The New York Times David Nevins of Cohen Brothers Realty, at 623 Fifth Avenue. From a residential standpoint, 2012 might be considered the year of the penthouse. Rooftop apartments with stunning views and sky-high price tags have seemed to change hands every few months in New York, smashing sales records in the process. The top floors of Manhattan's office buildings can be just as dazzling, but lately their leasing prospects seem to have come back down to earth. In premier Midtown buildings, more than a half-dozen penthouses are now available, which is more than in recent memory, according to brokers, landlords and industry analysts. Many of them have been empty for more than a year. Those vacancies can in part be explained by a sluggish Midtown leasing market, whose vacancy rate has been stuck around 11 percent, they say. But penthouses, which often have cavernous rooms and quirky layouts, can present their own hurdles. Because they are usually the priciest of a building's units, cost can be a deterrent. Current average asking rents are $158 a square foot, according to CBRE, the commercial brokerage, versus $113 for lower floors. But while lower floors may have comparable views, penthouses can boast singular perks, like the duplex that crowns 623 Fifth Avenue, at East 50th Street, which is flanked by wide planter-lined terraces. "We can provide a place where tenants can sit outside and enjoy views of New York that are second to none," said David Nevins, senior vice president of leasing for Cohen Brothers Realty Corporation, the building's owner. On a recent tour of the space, Mr. Nevins pointed out the Chrysler Building, Bank of America Tower and 30 Rockefeller Plaza, as well as Rockefeller Center's skating rink. He said the 21,000-square-foot space previously was occupied by the investment bank Merrill Lynch and used mostly for meetings and parties. The space takes up the entire 35th and 36th floors, has wood paneling and wall-to-wall carpeting, and a large kitchen. In a stronger market, the penthouse, which has been available since March, could probably fetch annual rents of $150 a foot, but will likely end up leasing for between $100 and $125 a foot, he said. "It's pretty, we know that, but we also understand the realities of the market," Mr. Nevins added. Large floor plates for these kinds of spaces aren't that unusual. The penthouse duplex on the market at 499 Park Avenue, at East 59th Street, owned by Hines, totals 18,200 square feet. But more common among the current batch is the penthouse at 535 Madison Avenue, at East 54th Street, a 1984 building owned by the Park Tower Group. The space, which is perched on the 37th floor, measures 9,500 square feet space, has been available since early 2012 and is asking $125 a foot, according to Brian Gell, the CBRE broker who is marketing it. While the triangular space lacks outdoor space like a traditional penthouse, it does offer ceiling heights of 26 feet, which easily beats most of its competitors, Mr. Gell said. Reached by a private elevator from the 36th floor, the office is also secure, which the financial tenant that probably ends up there will like, he added. "All penthouses are not created equally," Mr. Gell said. Some are truly very special spaces, and some are just the top floor of a building. But having to transfer elevators to get to work can be a nuisance, says Andrew Levin, a senior vice president of leasing for Boston Properties, the developer, whose two available Midtown penthouses trumpet their direct elevator access. Indeed, six passenger elevators travel from the lobby to the 47th floor at 599 Lexington Avenue, at East 53rd Street, an 8,600-square-foot space offering views of a glittering East River. Boston Properties is asking $110 a foot in rent for the office, which has been on the market for a year. Its size may be a factor. Most office deals are for 5,000 square feet or less, said Mr. Levin, who may ultimately divide the space in half to make it easier to lease.