When I did a house in Kirkland (Seattle area, also quake area), we were told by the engineer to go solid concrete walls (but its also on a steep slope, 2 story one side ,three on opposite), they were 10" thk with rebers...a conc. blk wall "might" also hold up, BUT I`d say to check with a local structural engineer...
we build these also in Austin area ,Texas, also with solid concrete , no quake zone ,but slopes...
