Workers of the world, architects have a place for you - half a mile up

Charles Arthur reports on plans to house 25,000 people in a new generation of super-skyscrapers

The city of the future is in the air - literally. Architects in the West and the East are putting the finishing touches to plans for skyscrapers more than half a mile high which would provide a complete living environment for 25,000 people.

The prototype building has already been built in the form of the Commerzbank in Frankfurt which, at 300 metres tall, is Europe's tallest building. Although it is a commercial rather than a residential construction, Chris Wise, a London-based director of the Commerzbank's designers, Ove Arup and Partners, says that the bank meets all the ideals of super-tall buildings because it was designed "from the people outwards".

The first sites for the megablocks of the future will almost certainly be in or near the crowded cities of the Far East such as Shanghai, Manila and Seoul where space is at a premium but government funding, and the will to build, is not.

Kuala Lumpur in Malaysia already boasts the tallest building in the world, at 452 metres, and the next step, towards structures so tall and wide that they can accommodate a living, working population throughout the day, may appear within our lifetimes.

Mr Wise outlined the future in a paper given last week at the British Association for the Advancement of Science conference in Leeds.

"I think in the West it is hard to imagine a structure like that - in London, Frankfurt or New York," he says. "But in places where the population is growing extremely fast, it may be exactly the answer."

Designers have already solved the physical problems of super-tall buildings. "We use super-high-strength concrete and steel to carry the enormous loads, and sculpt the form in a wind tunnel to make it nearly as aerodynamic as the finest Ferrari," Mr Wise says. "It's just not quite as fast."

They will tend to be substantially wider at the base than at the top, and may need stabilising systems so they do not sway in the wind: that can make the occupants of higher floors seasick.

Another previous bugbear for high buildings was lift design: there was a limit on how high a lift shaft run by cables could be. But that can be solved by using lifts powered with linear motors, which would use electromagnetic power to raise the lift car. If the electricity supply is cut off, failsafe attachments would lock the lift in place.

The real problem of such structures, as with the tower blocks of the 1960s, is not with building them but with ensuring that people want to live there and can enjoy the experience, says Mr Wise. "It's social, not technical," he says.

The construction costs are comparatively low when set against the money that will be spent on rents, energy, and salaries of the people in such a building.

"If we look at the costs of a tall office building over its life, only about 1 per cent is used for construction," he says. Energy consumes 4 per cent of the next 50 years' costs, and salaries 95 per cent. For a building accommodating families, the salary factor would be even higher.

Yet the mile-high building would simply be taking the same number of people who typically live in a horizontal district within a city, and enclosing them in a vertical space. That means that "it would have to be very accessible", Mr Wise says.

Avoiding the errors of the tower blocks will be essential. Part of that was the lack of central space.

"In a tower block, people spend all their time looking out, away from the building," he says. "Even in a modern building, when you look towards the centre, there's just some room and then a lift shaft."

Breaking away from that towards an atrium-dominated design, with windows that can be opened and even gardens and recreation areas at different levels, is the dream that is now coming together on architects' drawing boards.

"It is not about buildings with security-controlled access and swipe cards," Mr Wise says.

But even so, the dream doesn't come cheap: Mr Wise estimates the cost of a building for 25,000 people at between pounds 1bn and pounds 1.5bn.

"It's 30 per cent more than a conventional building, and would probably need government funding, at least in part."

He does not think it should be the high-tech version of a council estate. "It's not some single block where people don't communicate between floors. Tower blocks put people in a box. We must avoid that."

Anyone for whom a tall building immediately conjures up the image of the stranded partygoers on the top floor in The Towering Inferno can rest assured that in the city of the future, even that risk will recede.

"The idea of having entire levels given over to gardens is that they will be a sort of refuge in the event of fire. That's why you would have those spaces."

So, joining the mile-high club could turn out to be no more complicated than getting in a lift and punching the button for the top floor.