(a) A landlord shall install at least one smoke alarm in each separate bedroom in a dwelling unit. In addition:
(1) if the dwelling unit is designed to use a single room for dining, living, and sleeping, the smoke alarm must be located inside the room;
(2) if multiple bedrooms are served by the same corridor, at least one smoke alarm must be installed in the corridor in the immediate vicinity of the bedrooms; and
(3) if the dwelling unit has multiple levels, at least one smoke alarm must be located on each level.
(b) If a dwelling unit was occupied as a residence before September 1, 2011, or a certificate of occupancy was issued for the dwelling unit before that date, a smoke alarm installed in accordance with Subsection (a) may be powered by battery and is not required to be interconnected with other smoke alarms, except that a smoke alarm that is installed to replace a smoke alarm that was in place on the date the dwelling unit was first occupied as a residence must comply with residential building code standards that applied to the dwelling unit on that date or Section 92.252(b).