Built County Hall for the London County Council, which was legendary for its Edwardian Baroque design. Helped design the Queen Victoria Memorial outside of Buckingham Palace, as well as the Victoria and Albert Museum's Admiralty Arch.
He attended the City of London School; he was mentored in etching by the famed Frank Brangwyn while at the Architectural Association. He was hired by Sir Aston Webb following his education.
He designed Royal Air Force bases during World War I after which he was elected a fellow in the Royal Institute of British Architects in 1921.
He married Ada Brown, Sidney James Longden's widow, in 1919; his father, Samuel Knott, was a tailor. He and his wife had no children.
He and Christopher Wren both became world-famous British architects.