He was the younger son of Joseph Ferguson of Carlisle, and was articled to the architect and surveyor John A. Cory.
[1][a] He spent some years in partnership with Cory, but most of his career was in single-handed practice.
The architectural styles he used were mainly Gothic and Norman Revival.
The latter were obtained through personal contacts, for example his work for William Armstrong at Bamburgh Castle, Northumberland,[5] and for J. J. Bibby of the Bibby Line in Shropshire.
[6] In the Buildings of England series Ferguson is described as being "a resourceful as well as a sensitive architect".