Mitsubishi Ichigokan Annex Warehouse (East No. 9 Building, West Annex)
[The ultimate pre-war Renovation]

This time, we will be looking at the warehouse attached to Building No. 1, which was quietly built in 1906 (Meiji 39) behind the former Mitsubishi Ichigokan (completed in 1894 (Meiji 27)) (facing Naka-Naka Street). At the time, there was still no central station (Tokyo Station) and people commuted by streetcar or rickshaw, so the building was actually used as a rickshaw parking area (first floor) and a rickshaw driver's hanger (second floor). The two-story brick building has a floor area of 181 tsubo (approx. 620 m2) and a tiled roof. It has a vertically divided tenement floor plan and stairs between each section. The blueprint bears the seal of Yasuoka Katsuya. This building was used for about 60 years, until it was demolished in 1967 (Showa 42), after two major extensions and renovations, and was finally used as an office.

The first Renovation was in 1913 (Taisho 2), when one floor was added, making it three stories (expanding to 992m2). The extension method involved a reinforced concrete structure being placed discreetly on top of the brickwork. The details of the joints between the brickwork and the reinforced concrete remain as diagrams of the layout of the steel reinforced floor beams. Recently, there have been examples of SRC structures being added to the third floor of the Marunouchi Station building at Tokyo Station, but this was over 100 years ago. The ideas and technical capabilities of the engineers at the time are astonishing.

The second Renovation was around 1936 (Showa 11), when the building was converted into offices. The plan, which had been a vertically divided tenement house, was changed to accommodate whole-floor rentals or whole-building rentals by adding a new shared staircase to the center and openings in the brick partition walls between tenants. In addition, although there had previously been no entrances to the first floor on the Nakanaka-dori street side, renovations were carried out to create large openings, and an office entrance and car garage were installed. And whereas the building had previously had a featureless brick facade reminiscent of a warehouse, it was reborn as an office building in the style of a secession with decorative touches such as window frames, tiling of the lower part, and entrance fixtures.

By adapting its purpose and facade to the changing times, the Mitsubishi Ichigokan Warehouse has survived for over 60 years, and it is no exaggeration to say that it is the ultimate example of prewar Renovation architecture. We would like to continue to develop it further, inheriting the wisdom and spirit of our predecessors.