New York storeys

"There's no architecture being built in New York – just a lot of stuff," says Rick Russom of Peter Eisenman Architects. "New York is run by developers. The money drives the process."

This is true across the USA, but on the cramped, fabulously wealthy island of Manhattan, the effect is magnified spectacularly. The $300m (£210m) Trump World Tower, nearing completion on the Upper East Side, is a case in point. The 372 luxury apartments have price tags ranging from $1m (£700 000) to a cool $11.4m (£8m). At 72 storeys, it will be the tallest residential building in the world, with a height-to-width ratio of 11:1.

The project sums up New York, according to Kevin Murphy, vice-president of Bovis Lend Lease and project leader on the tower. "To me, it's an expression of the American ideal. If you ask anyone about New York, the first thing they think about is skyscrapers. That's how we made our reputation."

But the building has been highly controversial. Towering over a low-rise residential area, tycoon Donald Trump allegedly bought up the air rights for the surrounding blocks and transferred them to his site, enabling his tower to bust through the height ceiling set by zoning laws. The city is now considering tightening up the rules to prohibit such excesses – the Unified Bulk Programme would set height limits and outlaw Trump-style zoning transfers. But developers are fighting the proposal tooth and nail.

Do not go to New York looking for carefully detailed buildings – cost and speed drive everything. "Contractors in New York have told us that nowhere else in the world can build so fast," says Lance Hunter, MBA researcher at Bath University. "Owners want to have tried-and-tested solutions. They don't want any problems, which is why they're so limited in terms of innovation."

"They've value-engineered their buildings so much it's almost an art form," agrees Tony Mclaughlin, senior partner at Buro Happold New York. "The cost of materials drives everything. Building costs average about £91/ft²." Bill Pedersen of architect Kohn Pedersen Fox agrees. As a rule of thumb, he says, buildings in New York cost the same in dollars as they cost in London in pounds. In New York's frenzied rip-down-and-replace real estate market, buildings are also designed for a shorter life, usually only 25 years.

Urban design is often an alien concept and public space is usually an afterthought. Developers can gain approval to build tall in return for creating parks or covered plazas at ground level, but often these are closed off for "security reasons" after a short time.

And the city has been rocked by scandals over Mob influence in construction. In September, 38 people, including members of the Lucchese crime family, were indicted after a three-year investigation into bribery, bid rigging and other anti-competitive practices that siphoned millions of dollars from public and private projects. The prosecutor said contractors hired non-union labour and paid less than market wages, but billed clients for union rates.

The criminals used part of the proceeds to bribe corrupt union officials to look the other way, and to pay a 5% "Mob tax" to the mafiosi controlling the racket.

However, under mayor Rudolph Giuliani, New York has worked hard to shed its Mean Streets image. The city is spotless, crime levels are down and the subway works like clockwork. Times Square, once a haven for drug pushers and the sex industry, has been cleaned up and is becoming a focus for construction activity. A public-private consortium called the 42nd Street Development Corporation is overseeing the redevelopment of a 5.25 ha area around the square. A rash of commercial towers are rising here, including what is billed as America's first green skyscraper. The corporation is trying to discourage monotony by insisting on a range of different architects for the projects.

The Times Square scheme generating most interest is Renzo Piano's competition-winning proposal for a new headquarters for the New York Times. Herbert Muschamp, the newspaper's influential architecture critic, hailed the news that the Italian was to build in the city as the most exciting architectural prospect for decades. "Since the 1970s, the reigning law in New York building has been: thou shalt not commit architecture here," Muschamp wrote last month. "That rule will now be shattered by Piano."

Piano's scheme, featuring floors cantilevered from a central core and a suspended triple glass facade, is radical compared with the normal shell-and-core tower. "It's not the way it's normally done here," says Bruce Fowle of architect Fox & Fowle, which has teamed up with Piano for the job. "There's not normally a lot of relationship between the architecture of the facade and the core."

Fowle adds: "Cantilevering the floors will be a major cost differential compared to how we usually do things here." He says the extra expense would make most developers shudder, but adds: "This building is going to be so unusual and so desirable it will have its own market value. Developers need to learn that."

There are signs that a more European sensibility is creeping in as the city sets about catching up with the global trend for signature buildings. A new breed of "boutique" architects, led by young practice Sharples Holden Pasquerelli, is challenging the norm. Its translucent Museum of Sex will be one of the city's architectural highlights when built. Meanwhile, Frank Gehry has proposed a new branch of the Guggenheim on the East River. New York, which did so much to define the 20th-century city, may be about to get a landmark building for the 21st.