30 St Mary Axe (informally known as the Gherkin) is a commercial skyscraper in London’s primary financial district, the City of London. It was completed in December 2003 and opened in April 2004. With 41 floors, it is 180 meters tall and stands on the sites of the former Baltic Exchange and Chamber of Shipping.
The building uses energy-saving methods which allow it to use only half the power that 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 promote double glazing in residential houses, which avoids the inefficient convection of heat across the relatively narrow gap between the panes, but the 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.
On the building’s top level (the 40th floor), there is a bar for tenants and their guests, with a panoramic view of London. A restaurant operates on the 39th floor, and private dining rooms are on the 38th. Most buildings have extensive lift equipment on the roof of the building, but 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 lift only reach the 34th floor, with a separate push-from-below lift 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.
The building is visible over long distances: From the north, for instance, it can be seen from the M11 motorway, some 32 kilometers away, while to the west it can be seen from the statue of George III in Windsor Great Park.
Since its completion, the building has won a number of awards for architecture. In October 2004, the architect was awarded the 2004 Stirling Prize. For the first time in the prize’s history, the judges were unanimous. In December 2005, a survey of the world’s largest firms of architects published in 2006 BD World Architecture 200 voted the tower as the most admired new building in the world.
According to Wikipedia