(1) Any rates, rating schedules, or rating manuals for a new or renewal fire insurance policy for an existing or newly constructed building, whether used for commercial or residential purposes, must provide for a premium discount if a fire sprinkler system has been installed in the building in accordance with nationally accepted fire sprinkler design standards, as adopted by the department, and if the fire sprinkler system is maintained in accordance with nationally accepted standards.
(2) The discount required by this section must provide a premium rate that is lower than that for a building in which a fire sprinkler system has not been installed. A discount used by an insurer is presumed appropriate unless credible data demonstrates otherwise.