The Department of Planning and Local Government recently issued a warning that bunkers are not endorsed as safe refuge for bushfires. In the Victorian bushfires in February last year 7 people died in the bunkers that were supposed to protect them. The Department says that a house that complies with current building standards is regarded as the safest building on a property during a bushfire.
There are no Australian Standards for construction of bushfire bunkers. In some instances, this sort of structure may not even require Building Approval. The ACCC has warned that businesses advertising their bunkers as complying with Australian standards are misleading the public. The fact is that there are no such standards yet.
This is not to say that all bushfire bunkers are illegal, or won’t work properly or save lives. What is important is that each one must be built taking into account the conditions that exist on site. Of critical importance is the location of the bunker. Will part of the house or a large tree fall on the bunker during a fire, preventing the occupants escaping from their refuge? The bunker needs to be strong enough to withstand falling buildings, or be located far enough away from them. The structure needs to preclude the entry of smoke and have its own air supply. It needs to have a fire resistant window or peep hole so that whoever is inside it can tell when the fire has passed. It needs a facility to communicate with the outside world, water, food, first aid kit, a toilet facility and small fire fighting equipment like a knapsack sprayer.
These are only a few of the things to be considered when designing and building a bunker.