Half of the entire construction time and expenses were spent on the foundation works of AKARENGA-KAN, making it an extremely earthquake-proof building. First, the base was dug 2 meters deep, then raw pine log pillars (18cm diameter and 3.7m long) were driven in three lines at 60cm intervals. Then these were covered with pebbles and a thick layer of concrete. Upon this foundation, 11 layers of red bricks were laid which are under the visible outer wall bricks. The area under the concrete part of the floor was completely covered with mortar to avoid the damp from the soil –thus making the building also damp-proof.
The outer wall consists of two layers of red bricks (410-440mm thick). To substitute the weak points of the brick building as such, band-iron was set parallel to the ground among the layers of the bricks. On the wall crossings, round iron poles were put vertically and band iron fastened to them in the sharp shape (#) fixing each brick.
The two great earthquakes that struck Northern Japan after the construction was finished – the Oga Peninsula earthquake and The Japan Sea Central Part earthquake, not to mention the minor ones, didn’t leave a crack in this superbly fixed building!