The Three Courtyards House is an unbuilt residential project by architect Mies van der Rohe from the 1930s. The house is also part of a process of typological investigation of courtyard houses, lasting almost ten years of the architect s teaching and professional activity. The present work observes the design of the masonry wall of the house under the understanding of a progressive protagonism of this element, from its first studies to its last version, associated with the concept of architectural autonomy. Based on the comparison between the works of the investigative series and Mies s executed works, it is possible to notice that the masonry wall gradually ceases to mediate the architecture with the land and starts to dispute the protagonism with the house s internal space.