(a) The owner of an apartment house or mobile home park may submeter each dwelling unit in the apartment house or mobile home park to measure the quantity of electricity consumed by the occupants of the dwelling unit.
(b) Electric submetering equipment is subject to:
(1) the same rules adopted by the commission for accuracy, testing, and recordkeeping of meters installed by electric utilities; and
(2) the meter testing requirements of Subchapter C, Chapter 38.

(c) If not more than 90 days before the date an owner, operator, or manager of an apartment house installs individual meters or submeters in the apartment house the owner, operator, or manager increases rental rates and the increase in rental rates is attributable to the increased cost of utilities, the owner, operator, or manager, on installation of the meters or submeters, shall:
(1) immediately reduce the rental rate by the amount of the increase attributable to the increased cost of utilities; and
(2) refund the amount of the increased rent:
(A) collected in the 90-day period preceding the installation of the meters or submeters; and
(B) attributable to the cost of increased utilities.