The following is a summary of the content analyzed in this paper on the process of introduction of reinforced concrete structures for office buildings in modern Japan.
If one focuses on the structural forms and floor plans of office buildings constructed in the initial period of the introduction of reinforced concrete structures, it is confirmed that the process of introduction of reinforced concrete structures was significantly different for the Mitsubishi conglomerate and the Mitsui conglomerate, particularly during the initial period.
While the lineage of Mitsui was heavily influenced by the floor plan of the Mitsui Building No. 2, based on the steel structures of Yokogawa. All reinforced concrete (RC) buildings were introduced with the Mitsui Bussan Yokohama branch, which happened to have a structural form that was rather close to the rigid-frame structures of Endo. In other words, the lineage of Mitsui consisted of the introduction of steel structures and the development of architectural planning alongside rigid-frame structures in RC.
On the other hand, the lineage of Mitsubishi begins with the box-frame constructions and the Munewari Nagaya-style (partitioned tenement-house style) floor plans originating from the idea that concrete was a stone substitute. Later, with the expansion of the size of room space using a combination of wall and column beam structure, the reduction of cross-sectional area through the adoption of RC rigid-frame structures, and liberalization of floor plans, structural forms and the floor plans for large-scale, high-rise office buildings that could be reasonably managed were explored, and the above-mentioned lineage went on to merge with the Mitsui lineage.
Regarding the differences between the two business entities Mitsui and Mitsubishi in the introduction of the above-mentioned RC structures, the most notable factor is that it corresponds to the demand of the company business whether the purpose of construction of the office building is exclusively for company business, for lease, or a part of a large-scale district development. In other words, it reflected differences in the position of the construction businesses of Mitsui and Mitsubishi.
In this way, if one focuses on the business purpose at the time of construction, it is possible to add aspects such as assessment of plans that prioritize the reasonableness of land management, which considers business practices in historical evaluation, in addition to the assessment of which, one can include architecture and an understanding of who the pioneers in the introduction of new technology are.
