Revolutionary office block transforms London skyline

Copyright: David Lawson – Office Trends 2003

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30 St Mary Axe

At last Hollywood and CNN have an alternative to Big Ben, Tower Bridge and double-decker buses. How do you show the hero/investigative reporter is in Paris? A background of the Eiffel Tower, of course. Rome has its fountains, Sydney a clam-shelled opera house and New York  the Statue of Liberty. Meanwhile, London remained all cute and olde-worlde.

  Canary Wharf? Easily mistaken for US Anywhere. St Paul’s? A pimple on the horizon. The Dome? Too far away. The Lloyd’s Building? Tower 42? Even Brits are not sure where they are.

  Now a striped glass ovoid is the  new  icon. There is nothing like the new Swiss Re building on any city skyline. It creeps out from behind a clutch of anonymous square towers whichever way you approach the City, looking for all the world like a grounded spaceship. Fund managers from the planet Zog on a flying visit to check their bonuses.

  One small problem. Why did some smartarse have to dub it the ‘erotic gherkin’. You immediately feel sorry for poor Sara Fox, the project manager and a Swiss Re senior vice-president who has driven this revolutionary structure through to near completion with hardly a glitch over the last couple of years. But she’s seems remarkably laid back. ‘We see it as a term of affection nowadays,’ she says.

  Things weren’t always that relaxed. In fact the building, created by the ultra-fashionable Lord Foster, has caused more fuss than anything since similar attempts to put a landmark tower on the Mappin & Webb site in the heart of the City back in the Eighties. Ironically, that was also by an icon architect, Mies van de Rohe, and failed to materialise after being tagged a ‘glass stump’ by Prince Charles.

  More than 20 years on, the same kind of conservatism seemed ready to doom the project. But there were a couple of vital differences. A powerful and determined owner-occupier was willing to dig in its heels, and this time the planners came on board.

   It also sparked off the row over towers that is still going on. Standing on the 37th floor, you begin to see the attractions of skyscrapers. Broad circular column-free floors with 360deg views through a glass latticework across London. Great triangular bites through each floor, letting in yet more light. Even from the pavement it is magical.  ‘It seems to recede the closer you get,’ says City planner Peter Rees, clearly bemused by the optical illusion. 

  But reactions have not always been as positive and in the heat of battle, myths have emerged that clearly irritate Fox, dubbed the Iron Lady during a previous existence doing a similar job at Canary Wharf. Only recently, for instance, headlines shouted that the building was widening and sinking. Neighbours grew concerned that glass panels would begin popping, while the financial wires went into meltdown as investors home in Switzerland screamed for clarification.

  The gherkin’s girth has broadened. But it was designed to do so as the weight increased from the distinctive external steel lattice with every extra floor bolted on. As the final touches are applied, it is 125mm shorter and 25mm wider – not too serious for something 180 metres high and  16.5 metres wide.

  A more fundamental myth is that this is all a big vanity exercise. We’ve seen many a glossy HQ created by a top name to reflect the immense importance of the owner-occupier. But why go to huge expense and then keep your name off the building? 

  Perhaps because the firm is, to say the least, publicity-shy. Fox won’t even respond to queries about the cost of the site or building, a secrecy demanded from every member of the construction team. This is a little pointless when stock exchange notices back in 1999 revealed both [site = £85m; building and fitout = £130m].

  But leaving your name off a building is going a bit too far. Using the address, 30 St Mary Axe, is perhaps the best indicator that Swiss Re sees this not as a vanity but a commercial investment. ‘We always knew that around half building would be sub-let. The brief from start was that it had to be commercially viable,’ says Fox, dismissing early another myth that letting had been imposed from above.

   ‘But it still had to be built to the highest specifications – because it is ours - and sustainable – because that reflects the company ethos.’  The end result is a merging of these two drivers. The ‘green’ factor – primarily natural ventilation – reflect similar sustainable elements in Swiss Re buildings across Europe. ‘This is not a gimmick. It’s a global policy,’ she says.

   That had a fundamental input into the distinctive shape. When the firm went looking for a building after expanding rapidly in the late Nineties it could find nothing big enough. The recession had made developers wary of building 100,000 sq ft-plus blocks so that meant finding a site. But it had to be close to public transport, which cut down choices enormously. Because of the green principles, the only parking in the new building  is for disabled people, cycles and motorbikes. Even the chairman does not have a parking space.

  The bomb-blasted Baltic Exchange, which had been acquired by Trafalgar House,  seemed ideal.  It was big enough to provide the extra space Swiss Re wanted for future expansion and was not blighted by sightlines of St Paul’s, so a tower was not out of the question. But the firm was unhappy with both the existing permission for an Eighties-style, big-floor,  low-rise building  and the alternative plan by Foster & Partners for a tower twice as high as anything previously seen in the City.

  It also faced sniping over the ruins of the Baltic Exchange, raising one more myth about  bulldozing history.  ‘We were asked to consider keeping part of the remains, says Paul Scott, a director of Fosters.  ‘We looked at it but it was not seen as appropriate. In the end the Baltic itself agreed. So did English Heritage, which said it was better to restore the remains elsewhere . In fact the stained glass has gone to Greenwich for this reason’

  The new Foster plan met two crucial factors: it was green and suited the site. ‘People say the building could be dropped into any big city like New York. They are wrong,’ says Fox. ‘It is designed to fit this site in harmony with its neighbours.’

  The best ‘fit’ was circular. Creating harmony meant tapering the top to avoid bulk. Pulling in the base released some of the site to public space. That produced a cigar-shaped cylinder -  or to the fevered mind, an ‘erotic gherkin’.

  The stripes are not cosmetic. They reflect an internal revolution in its literal sense. Wedges were cut from the floors to act as a chimney for air to circulate. These are set in 5 degree ‘steps’, giving an upward revolving spiral from the tinted glass on each stack. The office space is protected by a double skin of clear glass which also vents stale air and allows fresh supplies to be drawn in from surface slots.

 The only thing that seem to be missing from early suggestions are the ‘sky gardens’ butr they may yet sprout in the light wells.  So Swiss Re has got what it wanted. The jury is still out on whether it is what anyone else wants. The firm wants to find an anchor tenant for the top of the building. A clutch of small ones will fill the middle floors on flexible leases to make way when the owner-occupier wants to expand.

  The biggest challenge could be persuading facilities managers they can fit standard office equipment into circular floors. Fox  is confident because the circles are segmented into ‘fingers’ of conventional space reaching out from the core. The best argument will be showing how Swiss Re organises its own space, although that may mean space will remain empty until the owner itself has moved in downstairs.


Prepare for more surprises on the skyline. Some ‘interesting’ new approaches are on the drawing board now the Swiss Re building is nearing completion. That might be dismissed a wishful thinking in the light of previous escapades that have come up against the brick wall of  conservatism, except that it comes from the most powerful   planning officer in the City Corporation.

   Peter Rees was once pigeonholed as a conservationist dedicated to preserving the City in aspic. But times have changed and in a new era when the Square Mile is fighting to hold onto its role as a leading financial centre against rivals like Canary Wharf and Frankfurt, he is refreshingly open about the importance of ‘exciting’ designs like the ovoid in St Mary Axe.     ‘Looking at Canary Wharf from my home the other day I thought how boring it looked with all those square buildings. Perhaps this will change things a little.’

  He insists it is not the planners who are suspicious of change but the public. The fact that the new design has received such a good reception will spur on other attempts to break with the past. Two ‘interesting’ schemes under discussion include Lord Rogers’ plan for  a British Land site at Leadenhall and ideas by Helmut Jahn for the DIFA in Bishopsgate.

  One fly in the ointment could be English Heritage. Ironically, it backed Swiss Re to the hilt over the revolutionary building when SAVE was fighting to preserve the Baltic Exchange, but then went on to oppose the Heron Tower.  ‘Very strange,’ says Rees.

  So does this mean the Corporation has changed its spots?  He insists the planners were never as dark as painted. The original Foster design took them back a bit – but it was  for gigantic tower. It also didn’t help that there had been no discussions. . ‘Plans came out of blue for the Millennium Tower. We were invited to a meeting and a model was lifted from a cardboard box of a building twice the height of Tower 42. [then the NatWest building and the highest in London]

  ‘There was an immediate outcry  which led to a lot of other buildings being kicked into touch,’ says Rees.  ‘But we were never against tall buildings. We never made an official comment.’

  Once it became obvious that even a shorter building would not get through, Foster switched to the ‘green’ tower and came up trumps. ‘We  had no input into the new shape,’ says Rees. ‘ In fact, we were reluctant at first about opening up the site as this exposed the sides of surrounding buildings that were never meant to be seen. But we were persuaded by the sheer quality of the building.’

  One of the myths surrounding the site is that the Baltic was betrayed when the City switched its policy and allowed a radical development after it was sold to Trafalgar House [which later passed it to Swiss Re]. ‘But they never asked us if they could clear the site and build a tower,’ says Rees.

 Permission already existed for a low-rise scheme which covered the whole site. It was the Royal Fine Arts Commission that recommended a tower when Trafalgar took over. ‘At the end of the day, the City is not for or against any particular approach. But we insist on quality, and this is what we got. The great thing is that many who were up in arms at the start are now full of praise for the building.’


Selling a strange new building to potential tenants is hard enough at the best of times. Plunged into the worst City slump for a decade, with alternative space pouring onto the market, could be soul-destroying.  But Swiss Re is confident it has produced something apart from the herd. ‘I’m not worried,’ says project manager Sara Fox. ‘At the end of the day quality counts. It will bring in partners.’

  She calls them partners rather than tenants because Swill Re is looking for a big name to take a similar long-term stake of up to 100,000 sq ft in the building. And that is where the weakness may lie, according to City expert Nick Baucher of CB Hillier Parker. ‘It will get the best rents being struck at the time but I doubt they will  pull in more than £50/sq ft with all the competing space coming on the market.’

  He is also nervous whether larger potential tenants will cope with the unconventional floorplates. Yet for an uninvolved agent in a market renown for bitchiness, Baucher is remarkably complimentary. ‘It’s a marvellous addition to the skyline – and a lot more efficient than some conventional towers,’ he says.

  ‘It is good for the whole City because it shows the market has finally moved on. We have not seen real change since the mid-Eighties when Stuart Lipton was breaking the rules by building schemes like Broadgate. And look what a revolution that caused.’

  John Forrester of retained agent DTZ Debenham Tie Leung has never been one to show the slightest doubt in anything he has taken on. ‘The clock is not even ticking yet,’ he says. ‘Let’s wait until the building is finished and see what happens.’

  By then he expects enquiries to have recovered. ‘We are at the low point of the cycle. Normally there would be three or four looking for up to 100,000 sq ft. This year there have been none.’

   The middle half-dozen floors reserved for smaller firms shouldn’t be a problem. Every survey has shown demand for towers is greatest for this kind of tenant, which could not normally command such prestigious space.

   And when the big ones come out of the woodwork, the ‘green’ credentials will be an advantage rather than a drag, says Forrester. ‘Ten years ago at a similar stage in the cycle you would not have seen companies looking for these factors. Now they are concerned about running costs, the impact on staff and the importance of image.’   They won’t pay a premium, he says. But,  like Baucher, he believes the designs will put the building first in the queue.

  Lack of parking is no problem because it has been cheaper for some time in central London to use local NCP spaces. Tenants also have an eye on the future when they may have to pay a levy on parking. They can even breathe easier about the Disability Act as the building has 16 spaces allocated for disabled people.

   Unlike Baucher, Forrester believes the unconventional floorspaces will not be a problem. The cutouts are not part of lettable space but are merely a distributed internal atrium. ‘A potential tenant ran a test against conventional layouts and found it more efficient,’ he says. Unfortunately, that may have been Dewey Ballantine, reported to have decided instead on Paternoster Square at around £48.50/sq ft (£522/sq m) with  two years rent-free and a 10-year break on 18,000 sq ft.

   The bottom line still rules for these intermediate tenants. It will take a giant as committed as Swiss Re to long-term sustainability over short-term costs to complete the circle.


It seems apt that a circular building should be hailed as a revolution, yet the  spectacular appearance of 30 St Mary Axe in some ways distracts from the real lessons it holds for the industry.   The shape and texture are essentially the result of problem-solving: how to get the best from a constrained, square site, how to meet environmental demands and how to do this in strict economic terms.  It had to lean, mean and green

  Early on, Foster & Partners enthused over ‘a lot of eurekas’ emerging during planning. ‘Every time we came up with one design it opened up new possibilities,’ it said.   But as the building nears completion  director Paul Scott is inclined to play down any hint of a space-age development.   ‘We used basic building techniques with a few tweaks,’ he says.

  The internal light and ventilation wells are also more the result of evolution rather than revolution  Maximising natural light and ventilation are common on the Continent, where Scott has much of his experience. Fosters has built on experience designing buildings like the Commerzbank HQ in Germany.

 The circular design meant triangular gaps left once the floors were divided into conventional office space. Adding two and two to make five, Foster took advantage of these dead areas to meet Swiss Re’s green demands, chopping them away to bring in extra light and fresh air. The building’s distinctive spiral reflects the 5 deg shift between each floor marked by tinted glass to cut solar gain, although fire safety requirement means these are cut off every six floors.

   Fresh air  is drawn in at each floor via slots in the edges of floor plates and exhausted into the lightwells. The twist, and the shape of the building,  create a the differential air pressure which draws air up the building. 

  The clear-glazed sections are a double skin for the office space. Each ‘finger’ of conventional floor area radiating out from the core has independent local environment controls relying on fresh air drawn in through  cladding slots and exhausting through the floor. The combined impact means occupiers should be able to turn off cooling and ventilation for 40% of the year. Foster estimates energy consumption at 140 kW/sq metre/year – around a third less than a conventional building.  

    The external lattice also reflects the process of designing the building ‘from the inside out’, says Scott. The shape demanded a skin which would provide structural support, so the designers came up with A-shaped steel modules which could be preassembled, lifted in and bolted together to form a rigid frame. Because of the inherent stiffness of the ‘diagrid’  the central core is required to act only as a load-bearing element and is free from diagonal bracing, producing highly flexible floor plates.

  The importance of engineers  in translating design ideas like this into reality is often overlooked. Letting agent John Forrester of DTZ Debenham Tie Leung goes even further in praise of Ove Arup & Partners.  ‘It is not just the technical detail. They created a building that worked for the wide spectrum of uses demanded by Swiss Re, ranging from big trading floors to more intimate spaces.’  

   Amazingly, there is only one section of curved glass in the whole block – the cone over the top floor restaurant. The curves come from carefully calculated angles between each module in the ‘diagrid’. This is not a simple building. The techniques may be evolutionary tweaks they needed cutting edge technology to assemble..  

   Write down the term ‘parametric modelling’ immediately.   It  will come up in planning meetings again and again as developers and architects seek more efficient ways to create flexible office buildings. This is a relatively new development in computer modelling developed in car and aircraft industries for designing complex curved forms. But it has a much wider potential.

  In simple terms, it is a three-dimensional spreadsheet which allows any element to be changed, automatically regenerating the design in the way a conventional spreadsheet adjusts figures.  Fosters says it becomes a 'living' model offering an unprecedented degree of flexibility.

  It meant main contractor Skanska could work out in advance with sub-contractors on every detail of the building. That revealed the inevitable clashes between elements such as ducting and steelwork, and hundreds were designed out before the start. A restricted site like this demands extensive prefabrication and delivery exactly to schedule. Eliminating clashes in advance meant sections such as plant pipework could be put together with confidence they would not clog up the fast-track construction.

Vital Statistics

Project team

Architect:                               Foster and Partners

Project management:           RWG Associates (UK) Ltd

Planning:                                Montagu Evans\ Richard Coleman Consultancy

Quantity Surveyors:             Gardiner & Theobald

Acquisition agents:               Knight Frank

Letting agents:                      DTZ Debenham Tie Leung

Structural engineers: Ove Arup & Partners

Mechanical & electrical

Engineers:                             Hilson Moran Partnership

Legal advisers:                     Linklaters & Alliance

General contractor:              Skanska Construction UK Ltd

Demolition:                            Keltbray Ltd

Piling:                                     Cementation Foundations Skanska Ltd

Sub- and super-structure:   PC Harrington Contractors Ltd

Structural steel:                    Victor Buyck – Hollandia Joint Venture Ltd

Cladding:                               Schmidlin (UK) Ltd

Lifts:                                       Kone plc

Top of building:                    Waagner Biro Lt

Cleaning equipment:            Street Craneexpress Ltd

Toilet Fit-Out:                        Swift Horsman Ltd