[1] He became a journalist, based in Letchworth, where he developed an interest in town planning and the garden city movement.
Through the association, he promoted low-density housing schemes, whether designed as new towns or as extensions to existing ones, and in 1913 he toured the United States speaking on this topic.
[2] After World War I, Culpin was president of the Belgian Society for the Reconstruction of Belgium, and he chaired the Standing Conference on London Regional Planning from 1926 until his death.
[1] Culpin became active in the Labour Party, for which he stood unsuccessfully in Islington North at the 1924 United Kingdom general election.
In 1925, he was appointed to London County Council as an alderman, serving until 1937, when he moved to become a councillor in Battersea North.