2002 NFPA 72
11.5.1* One- and Two-Family Dwelling Units.
11.5.1.1 Smoke Detection. Where required by applicable laws, codes, or standards for the specified occupancy, approved single- and multiple-station smoke alarms shall be installed as follows:
(1) In all sleeping rooms
Exception: Smoke alarms shall not be required in sleeping rooms in existing one- and two-family dwelling units.
(2) Outside of each separate sleeping area, in the immediate vicinity of the sleeping rooms
(3) On each level of the dwelling unit, including basements
Exception: In existing one- and two-family dwelling units, approved smoke alarms powered by batteries shall be permitted.
5.5.2.1
(9) For stairways leading up from a basement, smoke alarms or smoke detectors shall be located on the basement ceiling near the entry to the stairs.