Just a year ago, it seemed a string of skyscraper proposals were about to turn London into Chicago-on-Thames. Now, tall is out and once again the groundscraper is flavour of the month. Matthew Richards discovers that big offices are laying low
It's been a tough few months for skyscrapers. Their effect on the skyline has come under intense scrutiny, most recently the inquiry into plans to build the 183 m Heron Tower in the City of London. Fears of recession have cast a shadow over their economic viability, and the events of 11 September have called their safety into question. But while the tall buildings debate has hogged the limelight, a rival building form has sneaked back onto architects' drawing boards almost unnoticed: groundscrapers.

In the late 1990s, groundscrapers – large capacity structures that spread outwards rather than upwards – were perceived as squat and dowdy beside their elegantly elongated cousins. The low point for the design came in 1998 when an undistinguished and bulky proposal for the Baltic Exchange bombsite in the City of London was ditched in favour of Foster and Partners' curvilinear Swiss Re. Suddenly, everyone from Renzo Piano to Santiago Calatrava was queuing up to punctuate the skyline with dramatic towers.

"We have various ugly low buildings, whereas the tall buildings in the pipeline are all very good design quality," says a spokesperson for London's skyscraper-loving mayor Ken Livingstone. Proposals for tall buildings attract so much attention that only the best designs survive, the spokesperson adds, whereas ugly low-rise buildings get by unopposed. Even Philip Davies, London director of English Heritage and a bitter opponent of the Heron Tower proposal, admits that many groundscrapers are "pretty grotesque".

But recently, top architects have been reinventing the form, resulting in some designs that give skyscrapers a run for their money in terms of design quality and floorspace. In December, Foster and Partners unveiled plans for a 65,000 m2 building at the Spitalfields site on the edge of the City of London. This six- to 12-storey block contains 18,000 m2 more office space than the 40-storey Swiss Re tower. Another Foster building, the six-storey E E Tower Place development, containing 42,000 m2 of offices, is nearing completion beside the Tower of London.

Last autumn, Michael Hopkins & Partners launched designs for a 71,000 m2 block in London Docklands. Its height steps up from 11 to 20 storeys, and the block contains almost two-thirds of the floorspace of the 50-storey Canary Wharf tower.

And last summer, Swanke Hayden Connell received rave reviews for its 77,000 m2 Merrill Lynch Financial Centre, a giant building for 4500 workers, which slots almost invisibly into the City.

For campaigners against tall buildings in London, groundscrapers are an acceptable way of meeting business demands. "I prefer them to skyscrapers because they pay more respect to the streetscape," said Times columnist Simon Jenkins, who spoke out against tall buildings at a House of Commons urban affairs subcommittee hearing last month.

The recent proposals by Hopkins and Foster challenge the theory that groundscrapers make poor use of sunlight and leave no room for public space. Both designs consist of four elements of ranging heights linked together, which breaks up the visual bulk. The result increases the surface area of the building in relation to its volume, which means that more natural light can enter the interior. The external gaps between the "fingers" form sheltered spaces that are open to the public, giving the buildings a human touch.

Proponents of skyscrapers point to the economic need for more tall buildings, but the financial case for groundscrapers is equally compelling. Ken Shuttleworth, a partner at Foster and Partners, says: "Square foot for square foot, it's cheaper to build a groundscraper than a tower." He adds that developers prefer large floorplates because they devote a smaller proportion of space to lifts and corridors, leaving more rentable room. The message from Shuttleworth is simple: "Groundscrapers are what clients want."

"A big floorplate is the best way to house workers," agrees David Walker, a principal at Swanke Hayden Connell's London office, which designed the Merrill Lynch building. He says groundscrapers are the best option for "any organisation that has a large workforce and works in open plan" – a description that now applies to nearly all major companies. He expects the trend towards open-plan offices to continue because they have better interpersonal dynamics and use half as much floor space as a cellular configuration.

Simon Harris, a property consultant, says the same applies to Merrill Lynch's competitors' need for trading floors because "big banks can only work effectively on large floorplates".

A key document in the high versus low argument is a 1998 study by Building Design Partnership for the London Planning Advisory Committee, a body since subsumed into the mayor's office. This concluded that there was no economic need for more high-rise office towers in London. However, it stated: "New mid-rise office buildings of around 65 m are a necessary component of future office supply." The study amounts to a groundscraper's charter, and Peter Drummond, London office chairman at BDP, says: "Everything we wrote in 1998 still stands in 2002."

EH continues to cite that 1998 study to support its arguments for low-rise development. Its concerns are more aesthetic than economic – Davies says its main aim is to ensure that new buildings are in keeping with the surrounding area.

Another EH ally is the Prince of Wales, who launched a vehement attack on tall buildings at the "Building for the 21st Century" conference in London last December. The skyscrapers described in the Prince's speech sound like the terrifying dementors from the Harry Potter series: "They cast long shadows," he said. "They darken streets and suck life from them." He located London "firmly in the European tradition of low to medium-rise buildings", and said towers in the capital "seldom blend into either the streetscape or skyline with good aesthetic manners". After reminding the audience of tall buildings' economically inefficient floorplates, he added that heat losses escalate as one builds higher. The cost of sending water, air conditioning and elevators to the top floors adds further to skyscrapers' astronomical electricity bills.

Elsewhere in London, towers are actually being knocked down to make way for groundscrapers. Richard Seifert's unloved 100 m Drapers Garden tower is due to be replaced with a low-rise development. And Terry Farrell has designed a modest Home Office complex to replace the universally reviled offices of the former Department of the Environment in Marsham Street. He told BBC radio: "The new Home Office has friendly buildings, and the most interesting feature is they're low-rise; six to seven storeys. And we actually have more floor space than the tower blocks had."

In the aftermath of 11 September, high and mighty towers do not quite have the same corporate cachet. And with the world's three largest economies in recession together, low-rise, efficient office buildings could be the shape of things to come.