Tenn. Code Ann. § 68-120-111: Smoke alarms.

No newly constructed one-family or two-family dwelling shall be approved for connection of electric service on a permanent basis under § 68-102-143, unless the dwelling is equipped with a smoke alarm that has been:

(1) Listed in accordance with the standards of Underwriters Laboratories, or another testing agency or laboratory accepted by the state fire marshal; and

(2) Installed in accordance with the building construction safety standards adopted pursuant to § 68-120-101 and in accordance with the manufacturer's directions, unless those directions conflict with applicable standards adopted by the state fire marshal. Notwithstanding the building construction safety standards adopted pursuant to § 68-120-101, battery-operated smoke alarms shall be permitted when installed in buildings without commercial power.