What is the purpose of the building gherkin?

Answer 1

The building was constructed by Skanska, completed in December 2003 and opened on 28 April 2004.[2] The primary occupant of the building is Swiss Re, a global reinsurance company, who had the building commissioned as the head office for their UK operation. The tower is sometimes known as "Swiss Re Tower", although this name is not official.[13]

The building uses energy-saving methods which allow it to use half the power a similar tower would typically consume.[13] 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.[2]

Architects promote double glazing in residential houses to avoid the inefficient convection of heat, 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.