Building standards were first implemented in Japan in 1952 and were revised in 1981 and 2000. Apologies for not having an English source, but of the people who were killed because of the house or building that they lived in, 98% were living in a building/house that did not meet the standards of the 1981 revision to the building codes.
https://www.kobe-np.co.jp/rentoku/sinsai/20/rensai/201409/00...