If you have automatic sprinklers that risk goes away. An NZS 4517 residential system to is not all that expensive - maybe a third of the cost of your carpets or kitchen appliances. The life safety record of properly installed systems is this country is essentially perfect. Installation is not so easy if have an existing skillion roof or if you live in a multi-unit building, but in most houses it's quite simple.
For sure, smoke detectors are the next best thing - just remember that smoke alarms have no effect whatsoever on a fire. Having to decide whether to go further into a burning house to rescue your kids, rather than get yourself out immediately, is a decision best avoided.