Designed The Economist Building in London with her husband and business partner, Peter Smithson. Popularized the streets-in-the-sky concept; a member of the Independent Group whose work was featured at the Institute of Contemporary Arts' 1953 Parallel of Life and Art exhibition, as well as the 1956 This is Tomorrow exhibition.
She studied architecture at Durham University. She and her husband achieved recognition with the Hunstanton School project that employed variations on Ludwig Mies van der Rohe's techniques.
She worked in the architecture department of the London County Council before starting a practice with her husband in 1950.
Her family was residing in Sheffield, South Yorkshire, when she was born. She married Peter in 1949 after meeting him at Durham.
She and Maya Ying Lin both became notable female architects, albeit of different generations.