A house constructed to AS 3959 does not necessarily mean you have a great solution.
Building regulations - what fire attack mechanisms are and are not taken into account.
A regulated house does not necessarily mean you have a great solution. It takes a lot more than that, and a lot more wisdom and learning to build a really good resilient house.
Bushfire building regulation takes into account direct actions between large fire fronts and the building.
Bushfire building regulation only partially consider adjacent buildings, adjacent combustible objects, surface fire, tree and large branch strike, wind and wind-blown debris, and smoke.
I certainly would encourage people to determine their BAL attack level as a measure of working out whether they've got simply an ember attack problem, or a problem that also involves radiation for an advancing front or in the worst case the potential for the flames from this front to directly contact the house.
Structure-to-structure spread is also a major issue in areas where houses are in within reasonable proximity of each other (12m or less).