After Oxford, he spent a year travelling on the continent as a tutor before accepting an offer from his maternal uncle, Sir Arthur Blomfield, to become an articled pupil in his London practice in the autumn of 1881.
He found the atmosphere in his uncle's office uncongenial and the practice's traditional Gothic Revival output hard and soulless, although he gained valuable mechanical skills at draughtsmanship and site experience.
During his years in his uncle's office, the practice produced two uncharacteristic schemes (for work at Marlborough College and Shrewsbury School) that appear to foreshadow Blomfield's enthusiasm for classicism, and in the design of which he was presumably involved.
With this ground, Blomfield was involved in the founding of the Art Workers Guild and was at first made its Honorary Secretary, but he attended infrequently and when admonished about this, resigned in a huff.
In retrospect, however, he paid tribute to these efforts as formative in setting a new direction for architecture: "I think it is due to these young men of the 80s that the arts were rescued from the paralysing conventions of the Victorian era".
In 1890, with the idea of designing and making fine furniture, Blomfield, Ernest Gimson, Macartney and William Lethaby joined forces to establish Kenton & Co.
He played a major part in the completion of the Quadrant on Regent Street, London when Richard Norman Shaw withdrew from the project.
He was sixty-five in 1921, but continued working at a gradually decreasing pace into his late 70s, producing a large number of war memorials in the 1920s, including the Menin Gate in Ypres.
Together with the work of Blomfield himself, Sir John Belcher and Mervyn Macartney, the arrival of a serious account of architectural development in the 17th and 18th centuries led not only to the preservation of many previously neglected buildings of those periods, but also increased interest in the neo-Georgian style.
He died aged 86 on 27 December 1942 and is buried in family plot in the churchyard of St Michael, Playden, East Sussex, half a mile north of his country home Point Hill, Rye.