I live in Brisbane Ca. and I am trying to build a 2nd house on my property. The way the house is designed there is the need for an inordinate amount of foundation. The building is up hill and we need to dig quite a bit. I saw a pre-fab foundation on one of the "This Old House" shows. There weren't any hills involved, but I was wondering if that could be used in Earthquake territory and could it hold the hill adequately. Ultimately I am trying to find a way to keep my costs down so that the foundation doesn't cost more than the house. Any ideas......