In 1885 Caröe was appointed architect to the Ecclesiastical Commissioners and subsequently worked on numerous church projects including Gustav Adolf Kyrka in Liverpool (1886); Congregational Church, Huyton, Lancashire (1889-90); St. John the Evangelist in Stansted Mountfichet, Essex (1889-95); St. David's Church in Exeter, Devon (1897); St. Stephen's Church, Nottingham (1897); St. David's Church, Exeter, Devon (1897-1902); St. Michael in Edmonton, London (1901); St. Barnabas in Walthamstow, London (1902); St. Aldhelm's Church in Edmonton, London (1902); St. Paul in Camberley, Surrey (1902); St. Luke in Finchley, London (1903); St. Bartholomew in Stamford Hill, London (1904); Bishop's Palace, Southwell, Nottinghamshire (1907-09); St. Michael in Chiswick, London (1908); St. Peter le Poer in Friern Barnet, Middlesex (1910); St. John the Baptist in West Byfleet, Surrey (1912); St. Andrew in Oxshott, Surrey (1912); and St. Ninian's Church, Isle of Man (1913). He was also engaged in the repair of Canterbury Cathedral.

Caröe's secular work included various, schools, banks, shops, offices flats, and country houses, including boarding houses, Wycombe Abbey School, High Wcombe, Buckinghamshire (1898-1902); Martins Bank. junction of Brunswick Street and Castle Street, Liverpool (1890-94); alterations to South Lychett Manor, Lychett, Dorset (1900-04); Coleherne Court, Old Brompton Road and Redcliffe Gardens, Kensington, London (1901-1903); Church Commissioners' offices, Westminster, London (1903); 37-43 Park Street, Mayfair, London (c.1903); new buildings for Trinity and Pembroke colleges, Cambridge (1905-07); Main Building, University College of South Wales and Monmouthshire, Cardiff, now Cardiff University (1905-09); and St. Edward's House, Great Smith Street, Westminster, London (1906).

Following World War One Caröe was commissioned to design a number of war memorials including for Church of St Peter and St Paul, Cromer, Norfolk (1919-21); Stoke by Nayland, Suffolk (c.1920); Harrow on the Hill , Middlesex (1921); and Barrow upon Soar, Leicestershire (1921). He also designed a Boer War memorial to the Buffs and Royal East Kent Imperial Yeomanry for Dane John Gardens, Canterbury, Kent,

Caröe exhibited at the Royal Academy in London, the Royal Scottish Academy in Edinburgh, the Glasgow Institute of the Fine Arts, and at the Walker Art Gallery in Liverpool. He was elected a Fellow of the Royal Institute of British Architects (FRIBA) in 1890 and was President of the Architectural Association in 1895-96. He became a member of the Art Workers Guild (AWG) in 1889.

Caröe was the author of several publications including Sefton (1893) and King's Hostel, Trinity College, Cambridge (1909) and The Importance of the Historical Buildings of Cyprus (1931). He also edited ‘Tom Tower’, Christ Church, Oxford: some Letters of Sir C. Wren to J. Fell (1923).

After retiring Caröe moved to Cyprus. He died in a house he had built for himself in Kyrenia, Cyprus, on 25 February 1938.

A biographical file on William Douglas Caröe is available on request from the Enquiry Desk, Royal Institute of British Architects Library, London.

_{Text source: Art History Research net (AHR net)}