The absence of, the incorrect placement of, or the incorrect installation of smoke detectors is one of the more frequent issues we find requiring attention when conducting a  PrePurchase Building or Home Inspection.


Legislation in South Australia provides for compulsory installation of smoke detectors in newly built homes. Legislation also provides that smoke detectors are required to be installed by the purchaser within 6 months of the date of purchase of the home.

The other trigger that will require installation is if and when you might turn your home into  house for rent or occupation by others.

Smoke detectors must be located under clause of the Building Code of Australia between each part of the building containing bedrooms and the remainder of the house. The Building Code of Australia alarm further recommends to avoid smoke detectors being located in dead air spaces. It specifies they should be located at least 300 mm from the junction of wall and ceiling.


smoke Alarm location


locate smoke detectors away from dead zones


There are other requirements such as smoke detectors should also be located on each storey of a house where not already provided with a smoke detector. That applies even if the storey consists only of carparking, bathrooms, laundries and the like. The favoured location for such smoke detectors is in the path of travel people are most likely to take to evacuate the building.

Smoke detectors in houses under construction, where consumer power has been connected to the property must, under clause (c) of the Building Code of Australia , be connected to the consumer mains power. This is required to be completed prior to handover.

Clause 76B (3) of the Development Regulations 2008 requires the new owner of an older house must, within 6 months of title transfer, install smoke alarms either:

hard wired to the 240 volt household power supply (unless the dwelling is not connected to such a supply); or
powered by 10 year life, non-replaceable, non-removable, permanently connected batteries. This is a lithium battery detector not the removable 9 volt units used in most houses.