People are still confusing modular homes with mobile homes. They're are nothing alike, other than they traveled over the road. A modular is a stick-built home built in a factory. They are indistinguishable from a site-built home unless you look in the attic. They have to meet current codes, and are built on a permanent foundation. In some areas, they may not hold their value, since people persist in believing that they are mobile homes. A mobile home, or manufactured home, is what we used to call a trailer. They have a steel frame underneath, and may or may not be on a permanent foundation underneath, In many areas, they may not have to meet current code, and their re-sale value is dismal.
In many parts of the country, a dwelling has to meet code, which is getting more and more stringent. As of January, 2011, many areas will require residential fire sprinklers in new construction! And yes, they can stop you from living on your own land if you do not have a CO. In many parts of the country, you are no longer free to do any number of things on your own property. Sadly, we are no longer a free country. And if you think you own your property, try not paying your taxes and see what happens. Sorry to be a downer, but you better first check to see what is legal on your property, and I recommend you go by the book.
(Gee, I'm cranky tonight!)