[EvanAnderson]

On the theme of pre-fab (albeit not mail order): I'm in western Ohio and we have a few Lustron houses[0] left around. These were a post-WWII product. Once you know the design features they're easy to spot.

In the town where I live we also have the Hobart Steel Houses[1] that were a quirky proof-of-concept by a local manufacturer. My daughter's first school is located in one of these houses. Being able to stick magnets in nearly any surface in the house is bizarre and cool. The school uses this property to great effect. I don't see how they would have ever been economical, though.

[0] https://en.wikipedia.org/wiki/Lustron_house

[1] https://en.wikipedia.org/wiki/Hobart_Welded_Steel_House_Comp...

[nimajneb]

Those houses are cool. There's two next to each other near where I grew up. I noticed them in High School I think. I never knew what they were until a couple years ago when I watched a video about them. They look quite unique with the smooth panel looking tiles for the exterior.