[vandahm]

> there is no one reason why we dont have basements, but it is more likely to do with the fact that up north they have to dig deep (3-4 ft) for the frost line. If you are digging that deep anyway, you might as well go an additional 4-5 ft and build a basement.

In Minnesota, where I live, basements are definitely a byproduct of structural requirements. You have to dig 48 inches so that your foundation is under the frost line. But also consider that you don't want your front door to be at ground level, because then it might not open after a massive snowfall. So if you add up all that vertical space, you get about 7 feet, which is about the ceiling height of an unfinished basement.