Are the requirements for Dwelling Unit smokes covered in NFPA 70, or is this covered in NFPA 72?

Brendan, I'm not sure about NFPA 72, but the resi reqirements I use are straight out of CABO .

in california it's the california building code section 310.9.1.this is the 1997 uniform building code with cal. amendments.it is also found in the international residential code if you are in that area.

Depends on what you local jurisdiction has adopted. The wiring is NFPA 70, but placement and system requirements is NFPA 72, IBC CABO, BOCA, etc

BOCA requires in R2 and R3 type buildings to have a smoke detectors installed in

1)Each bedroom
2)Adjacent to the bedrooms
3)One on each floor

Additional requirements for split levels and such are included.

The SD's are required to be 120 volt, interconnected and battery-backup.

Additionally, our fire battallion chief said adjacent means no more than ten feet outside the door. Also, SD's cannot be installed within 3 feet of the edge of ceiling fan blades and/or any vents(supply or return)

Minnesota has a veritable shopping list of regulations. . .new construction, existing dwelling upgrades, rental dwelling, sale or refinancing (and probably another couple that slip my mind at the moment) all trigger slightly to very different requirements for smoke detection. That's for the State. Then local jurisdictions can, and do, ammend as they see fit. Some local fire marshalls have instigated new and/or additional requirements.

As Ron states, the wiring itself, to the smoke detector location, is by the NEC. The location and number of smokes is by other regulation that must be sourced from the AHJ.