By about 1990 it was clear that the Tate Collection had hugely outgrown the original Tate Gallery on Millbank and the organization decided to create a new gallery in London to display the international modern component of their collection. The building that is now Tate Modern was a former power station which had closed in 1982. Plans were formulated to build a footbridge to link the new gallery to the City. The fact that the original Tate Gallery was also on the river made a satisfactory symmetry, and meant that the two could be linked by a riverboat service.
Herzog and de Meuron won the international competition to renovate the building, consisting of a huge turbine hall, thirty-five metres high and 152 metres long, parallel to the older boiler house. The turbine hall became a dramatic entrance area, with ramped access, as well as a display space for large sculptural projects. The boiler house became the galleries on three levels running the full length of the building. The galleries are divided into separate but linked blocks, known as suites, on either side of the central escalators.
Above the original roofline of the power station the architects added a two-storey glass penthouse, known as the lightbeam. The top level of this houses a café-restaurant with stunning views of the river and the City, and the lower a members’ room with terraces on both sides of the building. The chimney was capped by a coloured light feature designed by the artist Michael Craig-Martin, known as the Swiss Light. At night, the penthouse lightbeam and the Swiss Light mark the presence of Tate Modern for many miles.
The project was completed in 2000.