(1) Each comprehensive plan which does not allow for the siting of manufactured homes on individual lots shall be subject to a review by the city of the need and demand for such homes. The review shall be completed by December 31, 1990.

(2) For the purpose of providing an optional reference for cities which choose to allow manufactured homes on individual lots, a "designated manufactured home" is a manufactured home constructed after June 15, 1976, in accordance with state and federal requirements for manufactured homes, which:

(a) Is comprised of at least two fully enclosed parallel sections each of not less than twelve feet wide by thirty-six feet long;

(b) Was originally constructed with and now has a composition or wood shake or shingle, coated metal, or similar roof of not less than 3:12 pitch; and

(c) Has exterior siding similar in appearance to siding materials commonly used on conventional site-built uniform building code single-family residences.

(3) Nothing in this section precludes cities from allowing any manufactured home from being sited on individual lots through local standards which differ from the designated manufactured home as described in this section, except that the term "designated manufactured home" shall not be used except as defined in subsection (2) of this section.