(f) "Extraordinary cost" means the cost, as determined by a qualified
professional, of installing equipment necessary to eliminate a shared
meter in a dwelling or portion thereof which is in excess of the amount
of rent for four months rental of such dwelling. The commission shall
adopt additional rules for determining extraordinary cost based upon
whether the amount of service measured by the shared meter that is
utilized outside the shared meter customer's dwelling is sufficient to
warrant the cost of such installation.
(g) "Legal impediment" means a restriction which prevents separate
metering, rewiring, or repiping due to zoning ordinances which limit the
number or type or location of meters in a building or due to the
historical significance of the structure or such other legal
restrictions as determined by the commission in its rules.
(h) "Shared area charges" means that portion of charges billed to the
shared meter customer which remains after excluding the estimated
charges for service used by the shared meter customer and where
applicable, a third party, for the period during which the owner
maintained a shared meter condition in violation of this section or six
years whichever is shorter.
(i) "Third party involvement" means that a third party whose utility
service was to be measured through another meter had caused or
benefitted from a shared meter condition.