Hi Mary,

The age of a home is important due to different retrofitting laws over the years. Newer is better. But every insurer has a mapping program they use to determine earthquake risk in a given area. ABAG maps are one I'm sure some use, but I think there could easily be a dozen out there. Soils do matter and those are included in the mapping programs insurers use for rating.

I found out recently that in some places in California there were no retrofitting laws until 1970. I was really surprised.

Petra