Was probably born in England; he was articled to Aston Webb for three years from October 1892 and on completion of articles in about 1895 remained with Webb for a further three years as an assistant. He was at Worcester College, Oxford for a year (1898), during which time he appears to have designed a cricket pavilion in Oxford (completed 1899), and in 1900 returned to work in Webb's office as clerk of works. He designed privately a small church at Haywards Heath in Sussex, unidentified. He won the RIBA Silver Medal for measured drawings of Clare College, Cambridge in 1898 and was elected an Associate member of the RIBA in 1900. In 1902 Tyrwhitt left Britain to work in Hong Kong for Denison, Ram & Cook but left for South Africa in 1904. Here he was employed by the PUBLIC WORKS DEPARTMENT in Pretoria from 1904 until 1907, rising rapidly to the post of assistant architect. His co-assistant architect, P EAGLE, was appointed chief architect in 1907, his earlier arrival in the PWD perhaps leading to the promotion. Tyrwhitt left South Africa at this point and returned to England.
During his time with the PWD he designed about forty schools, a number of post offices and other government buildings for the Transvaal. Furthermore, recognising the talent of young Gordon Leith, he 'insisted upon having Gordon Leith sent to England' (African Architect Aug 1911:63-4) in 1905.
In Britain Tyrwhitt set up his own practice in London where he remained from 1908 until 1935, specialising in country houses and farm cottages. His largest country house was Moulton Heath House at Newmarket in Suffolk (1929). Several of his buildings were illustrated in contemporary journals. For a brief period (1919-1920?) he was employed by the Ministry of Agriculture as supervising architect on various jobs, making studies on building in cob and terre pisè for them. He died in Teneriffe, Canary Islands. His daughter became Professor Jacqueline Tyrwhitt of the Graduate School of Design in the Department of City Planning and Landscape Architecture, Harvard University.
His daughter Mary Jacqueline Tyrwhitt (nicknamed "Jacky") also became an architect but left South Africa as a child.
ARIBA 1900. (ARIBA nom papers (1900); Afr Archt Aug 1911:63-4; CSL 1905, 1906; RIBA biog file)
All truncated references not fully cited in 'References' are those of Joanna Walker's original text and cited in full in the 'Bibliography' entry of the Lexicon.