London City Hall (United Kingdom) - the headquarter of government and the Mayor of London

In the building with 10 floors there is the seat of the authorities and the mayor of London.

The design of the building was selected through a competition in which 55 projects took part, of which the 7 most interesting were placed on the public exhibition, where visitors expressed their opinions on them .

Inside the building there is a 500-meter pedestrian passage, reminiscent of the one in the Guggenheim Museum .

A shape resembling a motorcycle helmet (or egg) was chosen to reduce the building area requiring artificial lighting, which reduces energy consumption. Thanks to this shape, the building uses four times less energy than other buildings of similar size.

The frame used for the construction of the metal weighs 2,100 tons, while the reinforced steel used is 1950 tons. In addition, 13100 m² of cement and 7300 m² of glazed panes were used.

At the top of the building there is a gallery and a meeting place with a viewing terrace.

In order to reduce electricity consumption, in 2007 solar panels were installed on the roof, which allowed the building to produce its own energy, the founder and constructor became the London Climate Change Agency .

There is natural ventilation in the building, windows are opened in every office, heat coming from computers and lighting is also collected and then re-used.

The building is equipped with a cooling system through the flow of water extracted from the ground, the used water is then used, for example, when flushing toilets.

The building is open to visitors from Monday to Friday from 8 am to 8 pm, and on some weekends.