Built in 1926, the Bauhaus in Dessau remains Walter Gropius's major work. One of the most famous buildings of 20th century architecture. Not only architect of the Bauhaus, he is also the director of this "School of Creation": the Bauhaus, both patron and client. It is the separate needs of the school that determine the design of the buildings, which are connected to each other. To each space its coherence, its own existence. Gropius opts for a nesting system: he designs an asymmetrical building, giving it a floating character, playing on different masses and different heights, advancing into space. As if in extension. The desire for transparency is omnipresent. The curtain wall of glass that clings to the three floors of the main parallelepiped is the most accomplished mark of it. The interior decoration is designed and built by the Bauhaus students. It is a total architecture for Gropius. Rationalizing construction, producing more economical and functional housing will remain the ambitions of this fundamental architect of the 20th century who had to emigrate to the United States.