30 St Mary Axe nearly oblivious to the tower's existence until directly underneath it. The building was constructed by Skanska, completed in December 2003 and opened on 28 April 2004. The primary occupant of the building is Swiss Re, a global reinsurance company, which had the building commissioned as the head office for its UK operation. The tower is thus sometimes known as the Swiss Re Building, although this name has never been official and has more recently fallen out of favour, since the company's main headquarters is in Zurich and the Gherkin name has become more popular. The building uses energy-saving methods which
30 St Mary Axe glass panels on the building. The cost of repair was covered by main contractor Skanska and curtain-wall supplier Schmidlin (now called Schmidlin-TSK AG). Since its completion, the building has won a number of awards for architecture. In October 2004, the architect was awarded the 2004 RIBA 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. However, Ken Shuttleworth, who worked for Foster and Partners