Building No. 4 (Naka 10th Building No. 1) (Meiji 37 - Showa 39)
[Marunouchi infrastructure]

Building No. 4 (completed September 30, 1904) is a three-story brick building designed by Sone Tatsuzo and built facing Babasaki-dori street. While flipping through the blueprints for Building No. 4, one drawing caught my eye. "Roads and sewer layout around Buildings No. 4, 5, 6, and 7." It was actually a blueprint for a sewer pipe. It is said that the first modern sewerage system in Tokyo was the Kanda Sewerage System, built around 1884-1885 as a brick-built culvert, but considering that this blueprint was drawn in 1904, it is certainly not surprising that such a blueprint existed in the historical context. This time, I would like to introduce the blueprint for this infrastructure rather than introducing the building.
This "sewer layout drawing" not only shows the piping route of the sewer pipes, but also the diameter of the pipes. Furthermore, if you turn the drawing over, you can see that even the cross section of the road is drawn. This is what we would call a civil engineering drawing today. In this era, just like today, when designing buildings, drawings were drawn by an "organization" design office that covered architecture, structure, facilities, and civil engineering. These remains may still be lying dormant somewhere.
Looking further into the blueprint for Building No. 4, we came across a cross-section of the toilets and washrooms along with a diagram of the water supply and drainage system. What's interesting is the shape of the urinals at the time. They were placed diagonally facing each other so that people could relieve themselves. This would be an awkward arrangement today... In addition, the blueprint for this building does not show any women's toilets inside the building...