Health and Safety

Taking care with materials, equipment and work procedures and dealing with hazards.

Smoke alarms

People who are sleeping do not smell smoke and are unlikely to wake up during a fire. The most effective way to ensure house occupants wake up and get to safety is to install smoke alarms.

On this page

  • legal requirements
  • maintenance
  • smoke alarms for the hearing impaired.

Legal requirements

Smoke alarms are a requirement under the New Zealand Building Code Acceptable Solutions C/AS1 and C/AS2 (for fire prevention) and F7/AS1 (for warning systems). Smoke alarms must have:

  • a hush button to silence the alarm for at least 60 seconds  
  • a test button
  • a sound level that complies with NZS 4514:2021 Interconnected smoke alarms for houses – not less than 75 dBA at the sleeping position and not more than 100 dBA at 1.8 m height. (The standard can be downloaded for free.)

Acceptable Solutions C/AS1 and C/AS2 were amended in November 2023 with a 12-month transition period that will end in November 2024. They require interconnected smoke alarms in all new household units and homes where there are renovations that require a building consent, or a change of use. The Acceptable Solutions cite NZS 4514: 2021 for the installation of alarms. With interconnected alarms, when one smoke alarm detects smoke, all alarms will sound. Models that connect wirelessly are available.

Installing or replacing a hard-wired alarm must be done by a licensed electrician.

Some of the key points of the standard include:

  • The alarms must be in all bedrooms, living spaces, hallways and landings, and on each level of a multi-level home.
  • Where a kitchen is separated from living spaces and hallways by closable doors, an alarm suitable for kitchens (which may be a heat alarm) must be installed in the kitchen.
  • Where they are required, alarms must be mounted within 10 m of each other in any direction.
  • The alarms can be hard-wired or operated with a long-life (minimum 10-year) sealed and non-removable battery. Where hard wired they must be tested and certified by a licensed electrical worker.
  • The interconnection between the alarms can be wired or wireless and hard-wired alarms can be incorporated into a security system.

Under the Residential Tenancies (Smoke Alarms and Insulation) Regulations 2016 all rental homes must have smoke alarms:

  • The alarms must be either hard wired or photoelectric battery alarms with a battery life of at least 8 years.
  • If alarms have a battery, it is the tenant’s responsibility to replace the battery when it is worn out.
  • There must be at least one smoke alarm installed in the sleeping space or within 3 metres of the entrance to the sleeping space.
  • There must be an alarm on each floor where there is a habitable space however having an alarm within each sleeping space is preferable.

Smoke alarms are a legal requirement in all sleepouts.


Vacuum over smoke alarms to avoid dust build-up, and test with the test button monthly. The smoke detection element can be tested annually with an incense stick. Battery alarms should be replaced every 10 years.

Smoke alarms for the hearing impaired

Significant numbers of people, especially among those over 70, have some form of hearing loss. Smoke alarms that warn purely through a high-pitched sound may not be enough for them, especially overnight when people take out their hearing aids. A specialised smoke alarm system may be required with an extra-loud and/or lower-pitch alarm sound, flashing strobe lights or vibrating under-pillow devices.



Updated: 24 March 2024