The building was placed on the registry of historic sites in 1994 – just 18 years after completion. Since then the urban context has changed considerably: a number of new cultural venues have opened, and high-end housing has been erected. The promenade that once ended near the theatre now continues eastward. And Lasdun’s building is not in sync with some of today’s technical and commercial demands. With these factors in mind the theatre administration commissioned Haworth Tompkins to develop a new master plan; the latter served as the basis for the theatre’s recently completed revitalisation and expansion. Haworth Tompkins’s “The Shed” – a temporary 225-seat theatre located on the bank of the Thames and sheathed in red timber boarding (see Detail 10/2013, p. 1120) – made it possible for the National Theatre to hold performances during the construction phase. This is already the second renovation in the theatre’s 40-year history: the measures implemented in the 2002 renovation by Stanton Williams included extending the foyer, inserting shops and redesigning the landscaping elements. Haworth Tompkins’s project removed many of the installations dating to that time; to a great extent the architects have returned the interiors to their original state. This applies above all to the main entrance in the elevation facing the Thames, which had been obstructed in 2002 by a bookshop. The building has also been opened up toward the east and the south: on the northeast corner a glazed restaurant replaces a delivery entrance, and the second largest theatre in the east has a foyer of its own. The perhaps most significant change was made to the side facing away from the river: the grey, windowless concrete-block facade is now the discreet backdrop for a 4-storey addition to the theatre. The new structure holds additional workshops for stage sets, as well as studios for lighting, digital production and special effects. Its form and colour concept defer to the existing building, but the detailing introduces new accents. Now the general public has the opportunity to see what happens behind the scenes.
Lasdun’s exposed-concrete building envelope remains intact. The improvements to the building’s energy efficiency, under the direction of Atelier Ten, pertain mostly to building services systems. The gas boiler was replaced by a decentralised combined heat and power station. The original cooling system gave way to an absorption cooling system. The new production facility is heated by means of a geothermal heat pump system.
