The residential inspection checklist for (final) smoke alarms/carbon monoxide alarms include:
Hardwired, interconnected, and installed to manufacturer’s specifications and listing (including installed back-up battery) ***Please note: Plastic dust covers must be removed.
Manually tested: interconnected and audible throughout house, including all attached or detached habitable accessory buildings.
In addition to bedrooms, hallways and at each floor level, smoke alarms are required where adjacent ceiling heights vary 24 inches or more, and where door openings / archways drop down 24 inches or more from the adjoining ceiling height, City amended section R314.2, I.R.C.
Carbon Monoxide Alarms:
Locate outside of each separate sleeping area in the immediate vicinity of the bedrooms. Required for all dwelling units with attached garage and/or containing gas appliance(s), section R315.1, I.R.C.
Manually tested in accordance with the manufacturer's specifications as listed under UL2034, section R315.4, I.R.C. ***Please note: Plastic dust covers must be removed.
Approved and listed combination smoke /carbon monoxide alarms may be installed to satisfy the above regulations. Also, in lieu of carbon monoxide alarms, a "carbon monoxide detection system" (detection and audible notification may be used). ***Please note: The system must be owned by the homeowner and shall be monitored by an approved supervising station, section R315.2, I.R.C.