Smithfield Poultry Market

The structural engineers were Ove Arup & Partners, led by Povl Ahm and Jack Zunz.

The building has a frame of reinforced concrete, clad externally with dark blue bricks.

The shallow structure only rises 30 feet (9.1 m) in the centre, and is supported by pre-stressed concrete edge beams with clerestory glazing below, so it appear to balance on its corners.

Arup were previously involved in large concrete shell roofs at Brynmawr Rubber Factory (1945–1951) and the Bank of England Printing Works at Debden, Epping Forest (1956), now operated by De La Rue.

The shell was cast first, and then lifted from its formwork as cables for the edge beams were put under tension.