This has some truth but not the whole picture. I recently listened to a fascinating Podcast from Freakenomics Radio called, "Are Japanese homes disposable?" where they discussed a huge cultural difference regarding how the Japanese view their homes. When they purchase a home, they usually tear it down and build a new one from scratch. Once a home is built, the Japanese invest almost zero money/effort into maintenance. The average half-life of a home there is 38 years compared to over 100 in the US (not just SF). Growth in their construction industry is rapid despite almost stagnant economic growth. Anyway, it was just super interesting and definitely worth a listen to, especially because "earthquake fear" is an overstated factor in their housing production.

I believe the point that mikeg was making is that the on average newer Japanese houses are more likely to be be built specifically earthquake-proof.

Actually, the low average age of houses in Japan is not at all due to the war (it's much smaller than 60 years), but due to cultural/economical issues: http://www.reddit.com/r/japan/comments/vv3bf/why_do_japanese...