A functioning smoke alarm is the foundation of fire safety in housing

A smoke alarm is mandatory in all homes. 

Smoke alarms can be either conventional battery-powered units or mains-powered units. Mains-powered smoke alarms also have battery backup in case of power outages. 

The function of a smoke alarm is to detect a fire and alert those in the space as early as possible. In order for the smoke alarm to react to smoke at an early stage and for the alarm siren of the smoke alarm to be audible everywhere, the home must have a sufficient number of correctly placed and functioning smoke alarms. Because smoke rises, smoke alarms are installed on the ceiling of the room. 

There must be at least one smoke alarm for every 60 square metres or part thereof.  In addition to the surface area, the placement of smoke alarms must take into account the shape of the home and room, as well as activities that pose an ignition hazard, such as charging electrical equipment. 

Smoke alarms must be kept in working order. Maintenance responsibility includes the regular replacement of smoke alarm batteries and the replacement of the smoke alarm when the device fails or expires. The service life of a smoke alarm is usually up to 10 years.

According to the rescue services accident statistics, almost half of fires in residential buildings occur in homes without a functioning smoke alarm. Based on other studies, it can be estimated that approximately 20% of homes have no smoke alarm. The obligations to purchase and maintain smoke alarms are fulfilled better in detached houses than in owner-occupied or rental flats.