4. The term "manufactured home" means a structure, transportable in
one or more sections, which in the traveling mode, is eight body feet or
more in width or forty body feet or more in length, or, when erected on
site, is three hundred twenty or more square feet, and which is built on
a permanent chassis and designed to be used as a dwelling with or
without a permanent foundation when connected to the required utilities,
and includes the plumbing, heating, air-conditioning, and electrical
systems contained therein; except that such term shall include a "mobile
home" as defined in paragraph five, and shall include a structure which
meets all the requirements of this subdivision except the size
requirements and with respect to which the manufacturer voluntarily
files a certification required by the secretary of housing and urban
development.