(a) Except as provided in subsections (b) and (c) of this section, the owner of each dwelling unit, hotel, motel, hospital, nursing home, jail, prison, and residential-custodial care facility shall directly wire the smoke detector to the power supply of the building.
(b) In each dwelling unit, hotel, motel, hospital, nursing home, jail, prison, and residential-custodial care facility which is in existence on September 30, 1978, or which is constructed under a building permit issued before October 1, 1978, or which is substantially rehabilitated, the owner may install a smoke detector which operates from a plug-in outlet fitted with a plug restrainer device if the outlet is not controlled by an on-off switch and if the cord connecting the smoke detector with the outlet is not controlled by an on-off switch.
(c) In each dwelling unit in a structure with only 1 dwelling unit which is in existence on September 30, 1978, or which is constructed under a building permit issued before October 1, 1978, or which is substantially rehabilitated, the owner may install a monitored battery-powered smoke detector.