From 1930 to 1932 he worked for Behrens in Berlin and between 1932 and 1936 was the only paid assistant in the Paris studio of Le Corbusier. During this period Neidhardt was involved in several major projects, including a department store located in Alexanderplatz, Berlin. He was also a recipient of second prize in a competition for the Yugoslav Pavilion at the Exposition Internationale des Arts et Techniques dans la Vie Moderne, Paris (1937). He returned to Zagreb in 1937 where he designed the Theological School for the Zagreb Diocese.
