Hugh trained at Cambridge and went on to do a Ph.D. in architectural history before setting up Cullum and Nightingale in 1986. In 1998 Hugh was awarded a fellowship at the Canadian Centre for Architecture in Montreal to write a book on Northern Italian Baroque architecture. On his return to England he set up Hugh Cullum Architects. He has continued to be involved in teaching and research as well as acting as architectural advisor or senior assessor to a number of RIBA-led competitions and is currently a juror for the RIBA UK awards. He is co-chair of the Bloomsbury Conservation Area Advisory Committee, a member of the Ecclesiastical Architects and Surveyors Association and has been elected a Brother of the Art Workers Guild. In 2013 he was added to the RIBA register of Specialist Conservation Architects.