Xringer, those are modular homes, which I hadn't even thought about. Modular homes are built in a factory and trucked to the site, while prefab homes just have the framing and some subassemblies done in a factory and are assembled on site.
Due to shipping constraints, the New World homes are 15.75' wide. Hence the olde-fashioned styling, and the large percentage of floorspace spent on hallways. Here's a link to the New World Homes floorplans:
http://blog.newworldhome.com/wp-cont...Small_1026.pdf
AC_Hacker, thanks for the link. I'm sure there's lots of good reading out there, but the signal to noise ratio is a bit low.