I recently got a copy of "A Field Guide to American Houses", from which I learned the term "vernacular architecture" and that all the house names you hear on TV (Victorian, Cape Cod, Ranch ...) are just one slice of architecture, "polite architecture", and historically not a very big one. The way most of us think of architecture today, an architect designs the building to some (not necessarily well thought out ;-p) philosophy and then you go and build it out of the appropriate materials.

In vernacular architecture, someone woke up one day and decided to build a house. They built it house-shaped, from whatever materials were cheapest and most available in their region at the time, using whatever techniques were common in said time and place. The patterns of vernacular houses in different times and places are fascinating; you're shining a flashlight through the region of a peoples' brains where the archetype "house" is stored and seeing what it looks like.