New York horror put skyscraper's future in doubt

Architecture

The sight of the collapse of the twin towers of the World Trade Centre has cast a doubt over the future of the skyscraper as the ultimate symbol of corporate power.

The combined attractions of iconic architecture and copious floor space had made the high building irresistible to planners in the world's great financial cities.

In London, commentators had hailed 2001 "The Year of the Skyscraper", with the Mayor, Ken Livingstone, backing plans for clusters of Manhattan-style high-rise office blocks across the capital.

But yesterday building experts were calling for a fundamental rethink of the safety implications of such a strategy after the vulnerability of tall buildings was so vividly exposed.

Aaron Morby, editor of Construction News, said: "This was the year of the tall building. There has been a lot of talk about building new towers in London. These buildings cannot be evacuated quickly. That starts to raise very significant issues."

Mr Morby said that it was impossible to protect any building against "a Boeing flying at cruising speed", but he added that skyscrapers attracted the attention of terrorists.

"By their very nature, they are iconic and it means that they are going to be targets from now on," he said.

He said that Mr Livingstone would have to "think seriously about the implications of building high".

A spokeswoman for the Greater London Authority said the mayor was convinced there was a demand for office skyscrapers "in certain areas".

She said: "He will require them to be of a very high design quality, surrounded by excellent public transport links in areas where there is demand for that kind of space."

The spokeswoman said it was too early to say whether the attack on the World Trade Centre would have any impact on the plans for London.

But in an interview with Building magazine published tomorrow, Tony Arbour, head of the GLA's planning committee, said: "If I was a prospective tenant or developer of a tall building I'd be scared – tall buildings are clearly seen as targets. They're trophy buildings – terrorists won't go for low rise buildings."

The executive editor of Building, Denise Chevin, said that office staff were unlikely to feel confident about going to work in high-rise buildings after Tuesday's events.

She said: "At the moment, no one would relish moving from the City of London to work in a tower at Canary Wharf. People would feel a bit squeamish about it."

Some workers at the Canary Wharf tower were allowed to go home early on Tuesday after fears that the terror attacks could spread to Europe.

In Frankfurt, German banks yesterday ignored calls by state government to abandon their skyscrapers as a temporary security measure.

More clusters of tall buildings are being planned and built in Paddington, west London and in Docklands in the east of the City.

The planned London Bridge Tower, designed by the renowned architect Renzo Piano, is set to have 66 storeys and at 360m high will be the tallest building in Europe, dwarfing the 50-storey Canary Wharf tower. Plans for the skyscraper have provoked conflict. Advocates say the "glass-needle" tower exemplifies the best of modern design; but English Heritage has likened it to a "spike through the heart" of the area.

A new skyscraper is also being built in the City of London on the site of the old Baltic Exchange building, which was itself the target of a terrorist attack.

But John MacArthur of the structural engineering firm Arup said that it was important not to see tall buildings as the sole targets of terrorists and that the skyscraper's days were not over.

He said: "The Pentagon was attacked and that was only a six-storey building. I don't think it makes a huge amount of difference whether the building is low or high; they are all prone to attacks by terrorists."

Mr MacArthur said that any "prestige building" with "large concentrations of people" was vulnerable.

He said: "People will reassess whether they want to concentrate their whole firm into a building. But to actually say that the tall building is going to be the necessary focus of the next attack would be wrong."

Ken Shuttleworth, a director at architects Foster and Partners, said that abandoning skyscrapers "would mean terrorists win".

Other experts said that the rapid collapse of the two towers would cause designers to re-examine plans for modern skyscrapers where structural capacity has been reduced to provide maximum floor space.