Building No. 21 (1914-1961) [From Sone to Yasuoka, and then to Sakurai Kotaro]

Marunouchi began with Building 1 by J. Condor, and developed into Buildings 4 to 7 by Tatsuzo Sone. Later, Buildings 8 to 21 were designed by Katsuya Yasuoka, and the streetscape of Babasaki-dori and Nakadori was completed. This article outlines what Yasuoka inherited from Condor and Sone, and what he passed on to Kotaro Sakurai later on. Yasuoka designed Buildings 8 to 11 on the north side of Nakadori, inheriting the relationship between the designs of Buildings 4 and 5 and Buildings 6 and 7 by Sone (the design of Nakadori was simplified compared to Babasaki-dori, and facade of the buildings facing it were made uniform), and on the south side, he designed Buildings 14 and 13, inheriting the design of Babasaki-dori. Buildings 14 and 15 are thought to have inherited Sone's design techniques, just like the north side of Nakadori. However, he did not simply inherit them, but added another twist to them. First, a tower-like design was added toward the intersection where buildings 14, 15, 18, and 20 face each other. Secondly, building 21, Yasuoka's last work, had a flat roof instead of the roof that buildings 20 and 30 had, making it a groundbreaking piece of architecture that attempted a transition from the British style to the large-scale American style. From then on, Sakurai developed architectural designs with flat roofs, and began to explore designs that could accommodate larger office buildings with greater depth.