Smoke Alarms and Security Systems

Smoke Alarms and Security Systems

Smoke Alarms and Security Systems

A contractor was recently asked to install smoke detectors in premises which already had smoke detectors connected to a security system. He queried whether he had to install different ones or if the detectors were compliant with current regulations.
FESA has commented that smoke alarms connected to a security system are not compliant with the requirements unless they are:

  • Permanently connected to consumer mains power
  • Not able to be isolated as part of the security system
  • Have battery backup and comply with AS3786.

They also commented that the location of smoke detectors must be consistent with Building Codes of Australia (BCA) requirements. Further, FESA stated that all smoke detection heads must be changed at least every 10 years as reliability severely diminishes after this time.

BCA regulations confirm this and state that smoke alarms must comply with AS 3786 and that smoke alarms must be connected to the consumer mains power where consumer power is supplied to the building.

In dwellings where the construction of the building does not permit a space to conceal the wiring and there is no appropriate alternative location to install a mains powered smoke alarm, then a unit powered by a 10 year life battery that cannot be removed from the alarm is permitted.

The wiring rules AS/NZS 3000/2007 section 4.6 states that where National Building Codes require Smoke detectors, such detectors may be connected to the lighting circuit or to an individual (on their own) final subcircuit. The use of a lighting circuit is preferred as it provides monitoring that the mains power is available, as failure of lighting in an electrical installation would be indicated by the non-operation of the lighting luminaires.

As a guide only, smoke alarm regulations apply to the following:

(Source BCA 2011 Vol 2 Section 3.7.2)

New homes, existing dwellings offered for sale, lease or hire. This requirement applies to houses, duplexes, villas, flats, town houses and apartments (BCA Class 1 buildings, Class 1a, Class 1b, Class 2 and Class 4 Buildings) and any boarding houses, guest houses, hostels, bed and breakfast accommodation, farm stay and the like-

  • With the total areas of all floors not exceeding 300 m² measured over the enclosing walls of the Class 1b building; and
  • In which not more than 12 persons would ordinarily be resident; or
  • Four or more single dwellings located on one allotment and used for short term, holiday accommodation, which are not located above or below another dwelling or another Class of building than a private garage.
  • Holidays homes and apartments or other dwellings made available for hire on a casual basis
  • Dwellings hired out to employees.

Smoke alarms must be installed in a Class 1a building on or near the ceiling in—

(a) Any storey containing bedrooms—
(i) between each part of the dwelling containing bedrooms and the remainder of the dwelling; and
(ii) Where bedrooms are served by a hallway, in that hallway, and
(b) Any other storey not containing bedrooms.
Suitable smoke alarm locations

Drawings courtesy BCA Vol 2 Section 3.7.2

electrician perth smoke alarms location

For further information about smoke alarms and other types of buildings, please refer to the Building Codes of Australia 2011. Also refer to FESA website and AS/NZS 3000

For more information, please contact NECA’s Technical Department on 1300 NECA WA or email


Office Address: 3/16 Fortitude Boulervard, Gnangara, 6077

Mailing Address: PO Box: 1599 Wangara 6947

Phone: 6169 1679


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