It's the new London City Hall, seat of power of the Greater London Authority [GLA], which is the successor to the Greater London Council, shut down in 1986 by Margaret Thatcher. City Hall is home to the Mayor of London, the London Assembly and the 600 or so permanent staff who work for the GLA. For 14 years London was the only major city in the world with no central administration, but in 2000 Londoners once again elected a mayor, by the name of Ken Livingston! City Hall was designed by Foster + Partners, one of Britain's leading architects, whose design brief was to create a building for the GLA that would become a new landmark for the capital.
The GLA is leasing City Hall for 25 years.
The City Hall building's form is derived from a sphere, which has approximately 25% less surface area than a cube of the same volume. The building leans back towards the south, where floor plates are stepped inwards from top to bottom, providing natural shading from the most intense direct sunlight.
This 10 level building is naturally ventilated, with windows that can open in all office spaces. Heat generated by computers and lights is recycled. The deep-plan floors allow for the collection of heat at the building's core, which can then be redirected to its periphery. The combination of all these energy saving systems means that there is no need for chillers in the building.
Electrical consumption is reduced by avoiding refrigeration and using cold ground water to air-condition the building. The water is extracted from the water table beneath London via two bore holes and is used to cool the building and then in toilets and for irrigation savings on mains water. — at Tower Bridge.