Counterpoint is the theory of polyphonic music developed with the purpose of balancing the chaos and homogeneity of the relation of multiple melodies. In architecture, Le Corbusier refers to this term, and he also positions that kind of musical method as a "third solution" that differs from both complete chaos and complete homogeneity.

　According to this background, the aim of this study is to clarify how the arrangement of elements in architecture was controlled by the contrapuntal technique. For that purpose, I converted the color arrangement of two types of Le Corbusier's "Unité d'habitation" into graphs according to the hue, and analysed them in the same way as the musical notation.

　Firstly, the following principles were confirmed throughout the whole: "rhythmic contrast", the rule to shift the position of the movement and pause for each series, "complexity of progression" , to make the change of the relation of each series vary, "discrepancy of peaks", to make the position of the highest or the lowest tone different by each series.

　Secondly we focused on the more local part of the series and clarified the following common techniques were also observed in the various parts in the color arrangement of Unité; “pedal point", the method to intentionally keep the single tone to contrast it to the other changing series, "imitation" in which a part of series is repeated in another series straightly or inverted horizontally or vertically.

　By the counterpoint methods as mentioned above, the color arrangement of Unité seems to have acquired complexity which is different from mere random. In the planning stage, Corbusier had tried to compose the elevation of Unité by the more complicated arrangement of form, not colors. However, the uniform pattern of brise-soleil occupies most part in realized one for mainly economic reasons. As Le Corbusier called architectural colors "architectural camouflage", contrapuntal color arrangement complements the monotonousness of form.

　Besides, it was proven that the same kind of contrapuntal property as seen in the facade exists in the color arrangement of doors of each room facing the corridor which Corbusier called “interior road”, where the arrangement of 5 colors is repeated according to the order of color spectrum. "Complexity of progression" and "discrepancy of peaks" are realized thanks to shifting the arrangement by each side across the corridor.

　As an additional consideration, the arrangement of different types of Unité is compared to make clear that the series on the left end of type Marseille was diverted to type Reze and the right end was not. That fact also proves that there is a similarity between Le Corbusier’s way to determine the color arrangement of Unité and the musical method; horizontal notation with the direction left to right.

　From the above discussion, we can conclude that the expression of coexistence of order and complexity in the color arrangement of Unité is realized by means of the contrapuntal method similar to that in music, and it is equivalent to the method Corbusier called “third solution” learned from music.

　This study contributes to raising the resolution of the analogy of music and architecture. Further studies are needed to apply these analyses into form, dimension, and other factors of architecture and establish to the general architectural theory based on the theory of counterpoint.