Smoke Detectors Required: Smoke detectors shall be installed in each sleeping room, outside of each separate sleeping area in the immediate vicinity of the sleeping areas and on each additional story of the dwelling, including basements and cellars but not including crawl spaces and uninhabitable attics. In dwellings or dwelling units with split levels, a smoke detector needs to be installed only on the upper level provided the lower level is less than one full story below the upper level except that if there is a door between levels, then a detector is required on each level. All detectors shall be interconnected such that the actuation of one alarm will actuate all the alarms in the individual unit and shall provide an alarm that is audible in all sleeping areas. All detectors shall be approved, listed, and shall be installed in accordance with the manufacturer's instructions.

Alterations, repairs, and additions: When alterations, repairs, or additions requiring a permit occur, or when one or more sleeping rooms are added or created in existing dwellings, the entire building shall be provided with smoke detectors located as required for new dwellings. The smoke detectors are not required to be interconnected unless other remodeling considerations require removal of the appropriate wall and ceiling coverings to facilitate concealed interconnected wiring.

Power Source: Required smoke detectors shall receive their primary power from the building wiring when such wiring is served from a commercial source and, when primary power is interrupted, shall receive power from a batter. Wiring shall be permanent and without a disconnecting switch other than those required for over current protection. Smoke detectors shall be battery operated when installed in buildings without commercial power.

There shall be a smoke detector in the furnace room.

Carbon Monoxide Detector: A carbon monoxide detector is also required by the 2012 International Residential Code. Only one is required in the home, preferably at a gas fired appliance, although not required at that exact location. A smoke/carbon monoxide detector combo unit can be used.