Install a minimum of two detectors even in single level homes. Install a smoke detector in each bedroom as well as the main corridor outside of the bedroom area. Install a smoke detector above stairwells.
Mount smoke detectors in the middle of the ceiling, if possible. If not, mount detectors on the wall, at least three feet from a corner and 4-6 inches from the ceiling. Keep detectors away from fans or air ducts. Avoid placing the detector too close to kitchen stoves and bathroom showers.