One thing I was seeing along the Williamette and Columbia rivers in the Portland area were what looked like fairly conventional houses that you might see on a suburban lot, but sitting on barges. The ones that I saw were in places where it was difficult to photograph them, so the best I could do was this photo across a parking lot. It turns out they're relatively common (and debatable) in parts of the Northwest. See: www.seattlepi.com/local/article/Seattle-cracks-down-on-houseboat-like-boats-2400872.php