In a previous post Raymond Yeung says...
Anyway, here comes more questions/comments:

1. I still haven't heard anything about post-tension. Did some digging
on newsgroup. This technique seems like a routine on modern building.
But it sounds like people here think wood-frame 2-3 storeys are safer?

Post tension construction has no direct relationship to earthquake
resistance unless the engineer was using P/T strands to resist
overturing forces (unlikely). Post tensioning allows for lighter floor
slabs spanning longer distances. P/T can be a very effective tool when
trying to design large column-free spaces, but this has nothing to do
with seismic resistance.

2. The tile roof looks pretty, but are they safe? Which material is safest,
affordable and reasonably durable?

If earthquake resistance is an issue then stay away from tile roofs.
They add weight in the worst possible place -- the roof. Tile roofs
are great for resistance to forest fires.


3. Any other features to avoid/desire, e.g. chimney, number/size of windows?
Would Singles Family House be better than Townhouse (due to connected walls
etc, if something bad happens next door, it would likely affect us also)?

Generally, masonry chimneys should be avoided in high seismic zones.
However, many new homes have metals flues with stone veneer on wood
framing. So, they only look like masonry, but in fact are not. If the
townhouse or single family residence is properly engineered then it will
make no difference.

--
Bob Morrison
R L Morrison Engineering Co
Structural & Civil Engineering
Poulsbo WA