2-879-334 - Historic England Archive/Heritage Images

Commonwealth Institute, Kensington High Street, Kensington, London, 07/09/1961. Workers installing precast concrete ribs for the outer roof section at the western corner of the Commonwealth Institute exhibition hall. Laing built the Commonwealth Institute between October 1960 and October 1962 to replace the former Imperial Institute that was to be demolished to make way for new facilities at Imperial College. The building consisted of a four-storey administrative block housing a library, restaurant, board room and conference hall and a separate two-storey b lock containing a cinema with an art gallery above, but the focus of the project was the exhibition hall with its hyperbolic paraboloid roof, the first of its kind constructed in Great Britain. The exhibition, designed by James Gardner, provided spaces where each of the Commonwealth nations could showcase their achievements and characteristics, primarily to school children as teaching aids to enliven history and geography lessons. The shell arch of the central roof section was of reinforced concrete, cast in situ using timber formwork with rough sawn boards to provide a textured internal surface whilst the four outer "warps" were constructed using precast beams and wood wool slabs, blocks of shredded timber bound together in a cement paste and left visible from the interior. The entire roof was then clad in copper sheeting over a layer of vermiculite. It covers an area of 33,700sqft, 183 feet square with the central section 93 feet square and ranges between 30ft high at its lowest and 80ft at the peaks.