As of April 1, 2019, NY State Law is requiring all existing homes to be equipped with 10-year sealed non-removable battery operated smoke detectors, or with a hard-wired interconnected smoke detection system. The smoke detectors must be located in every bedroom or other room used for sleeping purposes, in the hallway adjacent to those rooms, and one smoke detector installed on every other level of the home including attics and basements.
There is no permitting requirement for installing battery operated devices, however a permit is required to install a line or low voltage, hard-wired interconnected smoke detection system.