London's Bankside Power Station stood disused from 1981 until 2000, when it opened to the public as The Tate Modern. Herzog & de Meuron approached the conversion with a relatively light hand, creating a contemporary public space without diminishing the building's historical presence. The impressive cultural icon has since become the most visited museum of modern art in the world, revitalizing its formerly sequestered, industrial neighborhood. The original building was designed by Giles Gilbert Scott in the late 1940s and was decommissioned after just three decades of use. Situated across the Thames from St. Paul's Cathedral, the station's chimney stands as a counterpoint to the cathedral's dome.
Herzog & de Meuron chose to enhance the urban character of the building without detracting significantly from its form, allowing it to remain an experiential and visual piece in itself. The most apparent exterior alteration is the light beam set atop its roof, a horizontal contrast to the towering chimney. The light beam's minimal geometry and translucent glass clearly differentiate it from the dark masonry and detailed brickwork of the original facade. The transition between old and new is not always obvious, however architects referenced the industrial character of Scott's design in each detail, avoiding jarring interventions which might distract from the works of art. The heavy stair rails, cast iron grills, and unfinished wood floors harmonize with the original aesthetic.
In order to accommodate a broad range of art, Herzog & de Meuron replaced much of the power station's interior with galleries of differing sizes. They share an understated aesthetic, but range in height from five to twelve meters, illuminated by a variety of natural and artificial lighting. The power station's original cathedral windows span floor to ceiling in some galleries, echoed in rhythm and proportion by skylights overhead. The light beam's layers of translucent glass were specifically designed to filter daylight and artificially replicate its qualities at night. An extension designed by Herzog & de Meuron is underway, expected to open in 2016. It will offer additional display space as well as public areas for learning and making.