Building No. 13 (1911-1960)
[Detailed drawing of vault installation]

Building No. 13, which stood in the northern half of the Fuji Building site, which was demolished in 2015, was a work of Yasuoka Katsuya (1906-1911), who succeeded Sone Tatsuzo as the top architect at Marunouchi Architects. Looking at the floor plan, there are black dots in the thin brick walls between the windows... What on earth is that? Further investigation revealed a "detailed drawing of vault construction." It is a structure in which iron bars are inserted into the brick wall to tighten the entire wall from above and below. This is a new earthquake-resistant brick construction device that meets the demand for increased window area in rental offices. And some of the windows have double sashes. Looking at the drawings in order from Building No. 1, brick office architecture has steadily evolved. Earthquake resistance has changed from steel bands to vaults, heating has changed from fireplaces to steam, eaves bellows have changed from stone to terracotta, and so on. Building No. 13 can be said to be the perfect form of office architecture in the brick construction era.