30 St Mary Axe is one of contemporary architecture of the city and became iconic symbol of London. Designed by Sir Norman Foster and completed in 2003. It is the second highest building in the City of London. The skyscraper is built with ecological criteria and also known as the Gherkin or the Swiss Re Building. 30 St Mary Axe is commercial skyscrapers in London’s main financial district. The building stands on the former sites of Baltic Exchange and Camber of Shipping, a company that managed the maritime rents and dealt with the sale of boats which was destroyed utterly by the bomb placed by the IRA in 1992. The building takes the name from its location – address at 30 St. Mary Axe.
Architect Norman Foster was inspired by the design of aircraft. The building is built in narrow field 49 meters at the base, 56.5 at the widest part, the top floor is 26.5 meters and it gives the view of a rocket. It is 180 metres and 40 stories. The average area of the oval shape is 1.400 square metres per floor, at the level 16 its rise to 1.800 and drops to 600 in 34 floors, which provides with a form that presents resistance to a flow of air or water. The overall cylindrical shape makes the wind move around the building.
There are two main structures, diagrid and core, in the building of the tower. Diagrid is a primary structure which resisting horizontal and gravity loads. Series of triangles and horizontal support combine gravity into one, making the building to be stiff, efficient, and lighter than a traditional high rise. Diagonal bracing makes the structure resist wind forces instead creating stronger frame connection. Core structure resists gravity loads.
30 St Mary Axe is London’s first ecological green tall building and was designed to use recyclable materials. During the construction was used 10 thousand tons of steel, which 29% of it in the diagrid, 24% core columns and 47% beams. 5,500 square meters glass of 24,000 were applied for exterior cladding except for the dome, as triangular, diamond-shaped glass panels and foundation made up of 333 piles in 750 mm in diameter and 25mm in deep.
Ground floor and first floor made up of reception and a series of shops, third to the sixteenth floor is the offices and 38-40 floors are private dining areas. The basement is used for the parking only two wheelers, four wheelers are not allowed in the parking.
The glass dome, lens, of the building provides a 360-degree panoramic view of London. Build of 7.429 glass panes which are 24m in diameter and weighs 250 kg.
The building consumes about half the energy than other skyscrapers the same size. The six light-wells are expressed externally with the grey-tinted glass that counters solar glare. They serve as both a natural ventilation system and deliver natural light. Ventilation for the whole building is heavily dependent on the six shafts that the full extent the entire building. The shafts pull warm air out of the building during the summer and warm the building during the winter using passive solar heating. Windows and blinds are computer controlled, open when the external temperature is between 20°C and 26°C and wind speed is less than 10 mph.
30 St Mary Axe has won several awards among them are Best British Innovation in 2003, Best Central London Office Development in 2004.