Recently, there was a conversation on Twitter about insulation, which outside of Hokkaido has only caught on recently in Japan. I’ve heard more than once that Japanese homes are built for summer, but older, traditional Japanese houses did a fair job of conserving heat, since most were designed with roka (hallways) around the perimeter of the house, which meant there was a space between the walls of the inner rooms and the exterior walls and windows. But since the war and even before, Japanese houses have become boxier in order to accommodate smaller parcels of land near large cities so that middle class families could afford them. Since insulation per se wasn’t an integral consideration of traditional homes, no one really thought to incorporate it in the new style. People just bought more kerosene. Read More