Fifty-seventh Street occupies a rarified realm in New York's address book. It is the barrier between midtown and upper Manhattan, marked by Norman Foster's hybrid Hearst Building, I.M. Pei's dignified Four Seasons hotel, the flagship Tiffany & Co. store and Carnegie Hall. But the street's newest arrival may soon be its most prominent: One57, designed by French architect Christian de Portzamparc, will exceed 1,000 feet to become the city and country's tallest residential building.

The base of the building will have a 210-room Park Hyatt hotel in the base, topped by 95 condos that begin on the 39th floor. The interiors are to be designed by New York-based Thomas Juul-Hansen, who recently worked on HL23 by Chelsea's High Line.

Currently under construction, One57 is expected to open in mid-2013, but the project has already made waves with sky-high pricing. The uppermost penthouse, with six bedrooms and seven bathrooms, is asking $110 million, which would be a new record for the most expensive home ever sold in America. (The ask was raised from $98.5 million, in part because of the record $88 million sale at 15 Central Park West.)

In the wake of the still-lingering recession, the success of One57 may cement the arrival of a new boom. Its developer, Extell, would seem to be a strong representative of such, as one of the most active builders during the downturn. It is also constructing the International Gem Tower, a new office building in midtown's Diamond District. In 2012, Extell will break ground on Riverside Center, a massive mixed-use complex of five towers also designed by de Portzamparc that will be the final piece of the Riverside South neighborhood.

One57 was a long time coming. Back in 2005, Extell's chief Gary Barnett called de Portzamparc to begin planning the first scheme for the site, which was initially a larger square plot. Hundreds of more designs followed, complicated by the L shape of the parcel and the narrowness of the site.

The result is a tower that adapts its footprint into a cascading southern facade and a two different glasses arranged to evoke the energetic cascade of New York's verticality, according to the architect. Noting its slenderness and the suggested focus to the north, de Porzamparc describes the building in an email as a tribute to the great scene of Central Park.

It would be the second time de Portzamparc has made his mark on Central Park South. His New York debut was the Louis Vuitton-Moët Hennessy (LMVH) Tower, a crystalline, multi-faceted glass tower for the cosmetics company completed in 1999. It is located just a few blocks east of One57, on 57th Street. But despite being a world-class architect and winning the Pritzker Prize in 1994, de Portzamparc's work has been seldom seen in Gotham.

During New York's starchitect boom in the middle of the decade, he had a design at 400 Park Avenue South, but it never materialized. (The lot is now being developed by Toll Brothers and Equity Residential.) Instead, he was active in Europe, designing the Philharmonie Luxembourg, a concert hall with strands of circular rods forming an arrangement akin to harp strings, as well as the headquarters for the newspaper Le Monde.

And while the city has a reputation for being difficult -- land use attorneys are often said to be as important as architects -- de Porzamparc finds it refreshing. In fact, New York is very attractive, he said. There are fewer constraints than in most of our European cities.

De Portzamparc was born in Casablanca in 1944, studying the École des Beaux-Arts in Paris. He has a background in both architecture and urban planning, and said he admires Rem Koolhaas, Frank Gehry, Seijima, Herzog & de Meuron.

With that background, de Portzamparc seems an ideal fit for cosmoplitan New York. Incidentally, One57's initial customers are said to be predominantly wealthy foreigners, who appear to find the location and its views among the finest in the world.

And perhaps reflecting its worldliness, in November, Extell closed on a $700 million construction loan from syndicate that included Bank of America, Spain's Banco Santander S.A., Abu Dhabi International Bank, Capital One and the Bank of Nova Scotia.

But beyond the economics of architecture, de Portzamparc stresses practicality as a path to good design.

We need to rediscover the essence of the meaning of 'the use,' he said. Architecture is above all here for a better living. Every gesture, every shape must be justified by various reasons that would reinforce their reason to be, their use, and will give more sense to their beauty.

A rendering of One57 and the Central Park skyline, viewed from the north. (Atelier Christian de Porzemparc)