Essential Architecture-  London

The Swiss Re Tower


Norman Foster


30 St Mary Axe






590 ft (180 m) tall


Office Building
  The building from street level.
Looking south down Bishopsgate, one of the main roads leading through London's financial district.

Looking south down Bishopsgate, one of the main roads leading through London's financial district.

30 St Mary Axe is a building in London's main financial district, the City of London. It is informally known as "The Gherkin", and sometimes as The Swiss Re Tower, Swiss Re Building, Swiss Re Centre, or just Swiss Re, after its owner and principal occupier. It is 590 ft (180 m) tall, making it the 2nd tallest building in the City of London, after Tower 42, and the 6th tallest in London as a whole. The building is famous for its daring architecture by Pritzker Prize winner Sir Norman Foster and ex-partner Ken Shuttleworth. The building was constructed by Skanska.

History of the site
The building sits on the former site of the Baltic Exchange building, the headquarters of a global marketplace for ship sales and shipping information. On 10 April 1992 the Provisional Irish Republican Army detonated a bomb close to the Exchange. It severely damaged the historic Exchange building and neighbouring structures.

English Heritage (a government preservation society) and the Corporation of London (another London governing body) insisted that any redevelopment must restore the building's old facade onto St Mary Axe. The Exchange Hall was a celebrated fixture of the shiptrading company.

Baltic Exchange, unable to afford such an undertaking, sold the land to Trafalgar House in 1995. Most of the remaining structures on the site were then carefully dismantled; the interior of Exchange Hall and the facade were preserved and sealed from the elements.

English Heritage later discovered the damage was far more severe than they had previously thought. So, they stopped insisting on a full restoration — over the objections of the architectural conservationists who favoured reconstruction.[1]

London's Millennium Tower was proposed to be built on the site.

Origin of "Gherkin" nickname

In 1996 Trafalgar House submitted plans for a 1,200 ft (370 m) building with more than 1 million square feet (90,000 m²) of office space, with a public viewing platform at 1,000 feet (305 m). The plan was notable for its highly unorthodox floor plan, which resembled — some would argue — a slice of a pickle. The sub-editors at The Guardian newspaper coined the term, erotic gherkin, for the building.

Although Trafalgar House abandoned this plan, the nickname has stuck. This unusual building has also been called the "Gherkin", the "Towering Innuendo" [1], and the "Crystal Phallus" [2].

The planning process
Work in progress on the "Gherkin". Construction began in March 2001, the building was topped out in November 2002 and officially opened for business in early 2004
Work in progress on the "Gherkin". Construction began in March 2001, the building was topped out in November 2002 and officially opened for business in early 2004
On 23 August 2000, Deputy Prime Minister John Prescott granted planning permission to construct a building much larger than the old Exchange on the site. The planning process was absolutely crucial to how the building ended up looking.

The site was very special in London because it needed development, was not on any of the "sight lines" (planning guidance requires that new buildings do not obstruct or detract from the view of St. Paul's dome when viewed from a number of locations around London [3][4]), and it had housed the Baltic exchange. The interior was extraordinarily beautiful, giving the planners extra motivation and leverage.

The original plan for the site was to reconstruct the Baltic Exchange. GMW Architects proposed building a new rectangular building surrounding a restored exchange — the square shape would have the type of large floor plates that banks wanted. This proposal didn't get any buyers.

Eventually, the planners realized that the exchange was unrecoverable, forcing them to relax their building constraints; they hinted that an "architecturally significant" building might pass favorably with city authorities. This move opened up the architect to design freely; it eliminated the restrictive demands for a large, capital-efficient, money-making building that favored the client.

Another major influence during the project's gestation was Canary Wharf. At the time, banks and commercial institutions were moving to Canary Wharf in droves, because the area allowed buildings with modern, large floor plates. The City of London was not approving such buildings, forcing firms to disperse their staff across many sites. When the city realized the mass defection its policies were causing, it relaxed its opposition to high-rise buildings.

Swiss Re's low level plan met the planning authority's desire to maintain London's traditional streetscape with its relatively narrow streets. The mass of the Swiss Re tower was not too imposing. Like Barclay's City building, one is nearly oblivious to the tower's existence in neighbouring streets until directly underneath it. Such planning rules/goals create a city's visual identity — e.g. New York's plot ratio and setback rules have had an enormous impact on how it looks compared to cities with more conservative rules like London and Paris.

The building

The architects, Foster and Partners, crafted a distinctive cone-like shape to reduce the wind turbulence around the Gherkin. It was constructed by Skanska, completed in 2004 and opened on 28 April, 2004. Its design won the prestigious RIBA Stirling Prize for the best new building by a RIBA architect in 2004. It was the first time that the prize jury was unanimous in their decision. The building also won the 2003 Emporis Skyscraper Award for the best skyscraper in the world completed that year.

The building uses energy-saving methods which allow it to use half the power a similar tower would typically consume. Gaps in each floor create six shafts that serve as a natural ventilation system for the entire building (even though required firebreaks on every sixth floor interrupt the "chimney"). The shafts create a giant double glazing effect; air is sandwiched between two layers of glazing and insulates the office space inside.

Architects limit double glazing in residential houses to avoid the inefficient convection of heat, but the Swiss Re tower exploits this effect. The shafts pull warm air out of the building during the summer and warm the building in the winter using passive solar heating. The shafts also allow sunlight to pass through the building, making the work environment more pleasing, and keeping the lighting costs down.

At 180 m (590 ft), the building is the 6th tallest in London
At 180 m (590 ft), the building is the 6th tallest in London
Most tall buildings get their lateral stability from either a core column or by an unbraced perimeter tube without diagonals — or some combination of the two. This normally means that if they're designed to be just strong enough to resist wind load, they are still too flexible for occupant comfort. The primary methods for controlling wind-excited sways are to increase the stiffness, or increase damping with tuned/active mass dampers. With the help of structural engineers at Arup, Swiss Re's fully triangulated perimeter structure makes the building sufficiently stiff without any extra reinforcements.

Despite its overall curved glass shape, there is only one piece of curved glass on the building — a lens-shaped cap at the very top.

The primary occupant of the building is Swiss Re re-insurers, who had the building commissioned as the headoffice for their UK operation. As owners, their company name lends itself to the other popular term, the Swiss Re Tower, although this has never been an official title.

On the 40th floor, which is the building's top level, is a bar for tenants and their guests featuring an unrivalled 360 degree view of London. An exclusive restaurant operates on the 39th floor, and private dining rooms on the 38th.

Whereas most buildings have extensive elevator equipment on the roof of the building, this was not possible for the Gherkin since a bar had been planned for the 40th floor. The architects dealt with this by having the main elevator only reach the 34th floor, and then having a push-from-below elevator to the 39th floor. There is a marble stairwell and a disabled persons' lift which leads the visitor up to the bar in the dome.

Recent events
In September 2004, during London's Open House Day where many buildings which are normally closed to the public are opened for a weekend, the Gherkin had queues of people trying to get into the building. Some people waited over 5 hours to get their moment up in a special visitors' area on the 40th floor. This set the record for the most people ever to visit a site on an Open House Day.

On 25 April 2005, the press reported that a glass panel two thirds up the 590 ft tower had fallen to the plaza beneath on 18 April. The plaza was sealed off, but the building remained open. A temporary covered walkway, extending across the plaza to the building's reception, was erected to protect visitors. Engineers have begun examining the other 744 glass panels on the building.[2]

In December 2005, the building was voted the most admired new building in the world, in a survey of the world's largest firms of architects, as published in 2006 BD World Architecture 200.

Conversely, in June 2006, it was nominated as one of the five ugliest buildings in London[3] by viewers of BBC London News.

In fiction
30 St. Mary Axe featured prominently in one storyline of the Vertigo comics series The Losers, in which the building was depicted as the headquarters of a megacorporation with ties to a shady CIA operative. 
In The Christmas Invasion, the 2005 Christmas special of the science-fiction television series Doctor Who, the building is seen to have all its glass blown out by the arrival of an alien spacecraft. 
Woody Allen's 2005 film Match Point features scenes of the interior of 30 St. Mary Axe. The character Christopher "Chris" Wilton works in an office in the building. 
The 2006 film sequel Basic Instinct 2: Risk Addiction features the building as the location of the office of David Morrissey's character. 
The PlayStation 2 game The Getaway 2: Black Monday used the building as the fictional headquarters of the Skobel Group, and it is featured quite prominently in the game.