 Returning to civilian life, he enrolled at the École Centrale des Arts et Manufactures, obtaining his diploma in 1922.Lefacheux began his working life with a brief spell at the North France Railway Company, before joining in 1925 the Compagnie générale de construction de fours (General Boiler Manufacturing Company) where he would build his career until 1939, and where he became a director.In parallel, he began in 1929 a doctoral thesis which he would submit in 1935 on the subject of “The peseta and the Spanish economy”.