(1) All construction of and all plumbing, heating, and electrical systems installed in modular housing units manufactured, sold, offered for sale, or leased in this state more than six months after July 10, 1976, and before May 1, 1998, shall comply with the standards of the state agency responsible for regulation of modular housing units as such standards existed on the date of manufacture.
(2) All construction of and all plumbing, heating, and electrical systems installed in modular housing units manufactured, sold, offered for sale, or leased in this state on or after May 1, 1998, shall be at least equal to the standards adopted and approved by the commission pursuant to its rules and regulations as such standards existed on the date of manufacture. The standards shall (a) protect the health and safety of persons living in modular housing units, (b) assure reciprocity with other states that have adopted standards which protect the health and safety of persons living in modular housing units the purpose of which is to make uniform the law of those states which adopt them, (c) allow variations from such uniform standards as will reduce unnecessary costs of construction or increase safety, durability, or efficiency, including energy efficiency, of the modular housing unit without jeopardizing such reciprocity, (d) assure changes in those uniform standards which reflect new technology making possible greater safety, efficiency, including energy efficiency, economy, or durability than earlier standards, and (e) allow for reduced energy and snow live load requirements for those modular housing units destined for out-of-state siting if the receiving jurisdiction has such reduced requirements. The commission shall adopt as standards relating to electrical systems in modular housing units those applicable standards adopted and amended by the State Electrical Board under section 81-2104.
(3) Whenever practical, the standards shall be stated in terms of required levels of performance so as to facilitate the prompt acceptance of new building materials and methods. If generally recognized standards of performance are not available, the standards shall provide for acceptance of materials and methods whose performance has been found by the commission on the basis of reliable test and evaluation data presented by the proponent to be substantially equal to those specified.