sentences:  The Great Depression, beginning in 1929, had a disastrous effect on the New Building, because of Germany's financial dependence on the USA.Many estates and projects planned in Frankfurt and Berlin were postponed indefinitely, while the architectural profession became politically polarised, something symbolised by the sacking in 1930 of the Marxist Bauhaus director Hannes Meyer—who had stressed, with his collaborators Ludwig Hilberseimer and Mart Stam, the importance of working class and collective housing—to be replaced by Mies van der Rohe, whose Barcelona Pavilion and Tugendhat House had gained him a reputation as a purveyor of luxury to the rich, and proceeded to turn the Bauhaus into a private school.Important work within Germany continued into the early 1930s, particularly the Ring's Siemensstadt Estate in Berlin, which was planned by Hans Scharoun as a more individual and humane version of the 'existence minimum' residential housing formula.