What are they sitting on?

There's a "foundation" of sorts, even is it's just some large beams under the floor.

It's a pier and curtain wall, still permitted with conditions. The piers may not be obvious; or, I suppose, absent altogether.

This post was edited by worthy on Sun, Oct 6, 13 at 20:43

Our little place is in a former railroad town and the original houses are usually on railroad ties, or at least old timber of the same dimensions. We're looking at buying a larger old house in a more populated area and I was surprised to see the term "no foundation" pop up so often. Those places seem to be discounted heavily, so I'll assume that "no foundation" is realtor speak for "I don't know what I'm looking at, cash only and good luck with the county." Thanks for the info!