You use M9 and get off at station “Saint-Augustin“. Walk along Boulevard Haussmann.
After about 50m it is the building on the right side. You can also use lines M3, M12, M13 or M14 and get off at station “Saint-Lazare“. Walk along Rue Saint-Lazare until you reach Rue Joseph Sansboeuf. Turn left and you walk straight at the building on Rue Haussmann.
Or you use regional train line RER A and get off at station “Auber“ or use line RER E and get off at station “Haussmann – Saint Lazare“.
From the airport Charles de Gaulle you use RER B and change at station “Gare du Nord“ into RER E. Get off at station “Haussmann – Saint Lazare“.