 Work on the foundations began in late 1928 , and in mid @-@ 1929 construction started on the steel frame . The building was completed in 1930 after only 24 months , by employing rapid @-@ setting concrete , new construction materials and a round @-@ the @-@ clock workforce . Later in 1930 , the Frankfurt director of horticulture Max <unk> and the artists ' group <unk> Kreis developed designs for the 14 hectares of parkland that surrounded the building . The grounds , and the complex as a whole , were completed in 1931 at a total cost of 24 million Reichsmark ( 150 million DEM , 76 @.@ 8 million EUR in 2016 ) . 
