In World War One he served with the Canadian Engineers. By August 1930 he had returned to London where he formed a partnership with Sir John Burnet (1857-1938), Thomas Smith Tait (1882-1954) as Sir John Burnet, Tait & Lorne. Lorne subsequently remained with the firm until it was dissolved in c.1948. Burnet had died in 1938 and he and Tait had run the practice up until then.

During the late 1930s, Lorne spent some time in South Africa and in 1947 he returned to the country and formed a partnership with Kenneth Birch (1914-2010) as Lorne & Birch in Johannesburg. He subsequently remained in South Africa where he worked on a number of industrial and housing projects, particularly for mining concerns.

He died in Salisbury, Rhodesia [now Harare, Zimbabwe] in June 1963

Architectural projects by Lorne included Hampsted Golf Clubhouse in Hampstead, London (1931); Mount Royal Flats in London (1932); Buchanan Hotel in Glasgow (1933); Curzon Cinema in Mayfair, London (1933); flats in Berner Street, Stepney, London (1934); Chelsea House Flats in Chelsea, London (1934); Howard Hall Masonic Temple in Braintree, Essex (1934); Evelyn Court in Hackney, London (1934); Ey Infirmary in Glasg ow (1935); German Hospital in London (1935); Steel House in Westminster, London (1935); St. Dunstans Hospital in Ovingdean, East Sussex (1937); residence of the Marques and Marquesa de Casa Maury in London (1937); British Linen Bank in Johnstone, Renfrewshire, Scotland (1938); Wilberforce Housing Estate in Battersea, London (1938); Ecclesfield Town Modern School in Ecclesfield, Yorkshire (1939); 650 concrete houses for the Scottish Special Housing Association in Rosyth, Fife, Scotland (1941); Joseph Triton School in Battersea, London (1947); and a bakery and store in Plymouth, Devon.