Originally, mobile homes were built on a chassis with wheels, hence the "mobile" portion of their name. They were small, easily movable, and relegated mostly to mobile home parks, recreation sites, and the hearts of kitsch lovers everywhere.
The modern manufactured home is different. Modern manufactured homes are built on a frame instead of a chassis, do not retain wheels and axles, and feature much more sturdy construction.
The HUD code, enacted in 1976, is really what makes a manufactured home fundamentally different from a mobile home. The HUD code established federal standards for the building of manufactured housing. It involved regulating the construction and quality of all aspects of building a manufactured house, including:
It is important to note that before this time, these things were not federally regulated. The HUD code was a huge step forward in ensuring quality manufactured housing. Therefore the term ‘mobile home’ refers to an unregulated construction pre-1976, and the term ‘manufactured home’ refers to a housing unit that is constructed post-1976 following specific rules for design, durability and safety.