(Male) Almost the whole town has been wiped out by fire.
(Male) Every house in the area was burnt to the ground.
(Male) And as late as midnight houses were suddenly bursting into flames.
(Male) The fire just ripped through these houses.
(Dr Ramsay) The obstruction we constantly come against
is this concept of the houses just spontaneously
exploding due to the heat of the fire front.
We just haven't found any evidence to support that idea.
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(Narrator) In Australia sun worship is almost a national religion.
The summer brings with it the promise of warmth,
health and relaxation, but who will ever forget the
consequences of one searing hot summer a few years ago.
(Male) One minute it was just a tiny outbreak in a hill behind the town.
The next it was searing down, engulfing everything in its path.
(Male) In the summers following people looked to the skies with fear.
It was Ash Wednesday.
(Narrator) Even as the embers of Ash Wednesday were cooling
a wide range of people were on the scene of the devastation,
house owners, clean-up teams, insurance assessors
and researchers from CSIRO.
(Male) The veranda post is still there though.
(Dr Ramsay) Yeah.
(Narrator) Dr Caird Ramsay and his team worked 12 hours a day,
seven days a week to survey 1,150 of the houses involved.
They made some surprising observations.
(Dr Ramsay) You had one house virtually untouched
and next to it on a similar block you had a house of apparently
similar design and construction that was completely destroyed
and the question why immediately comes to mind.
(Narrator) So began a project to find out why buildings catch alight
and what factors contribute to their survival or demise.
The evidence they collected gave a completely new picture
of the way in which houses ignite and then burn down.
(Dr Ramsay) The whole house was obviously ablaze.
(Narrator) But any new theory would face tough opposition.
(Dr Ramsay) Well I think when people think about bushfires
and their houses they believe that the bushfire
is going to create such an enormous amount of heat
that their houses are just going to explode in flames.
(Narrator) There's just no evidence to support this popular myth.
What the researchers found instead was that houses
catch alight in three ways, by direct flame contact,
by radiant heat and most importantly, by embers
and combustible debris blown by the wind.
These embers are by far the most common cause of house fires.
At a recent demonstration Dr Ramsay and his colleagues
showed just how this can happen.
Burning embers ignite small fires and these gradually progress
until the whole house is involved.
The outcome of the CSIRO research has been a set of basic principles
for houses built in bushfire prone areas.
Houses should be designed to resist
the onslaught of embers and flying debris,
a simple roof shape with leafless gutters,
window protection, enclosed underfloor space and no timber at ground level.
But houses like this are the exception rather than the rule
as Dr Ramsay has found when he visits fire prone areas.
(Dr Ramsay) Well the first reaction of course is despair
when one sees that virtually every house has been built
without any attention to the principles that we try and get
across to people. We would believe that that indicates that
the majority of people don't take bushfires into consideration
when they are designing and building their houses.
(Narrator) In order to combat this combination of disbelief and apathy
Dr Ramsay has made a video in conjunction with Melbourne University.
It explains the realities of bushfires,
the principles of good house design for fire prone areas
and how to survive in your house during a bushfire.
It's based on CSIRO's survey findings
and years of exhaustive research and it's already made inroads into
the ignorance and mythology surrounding the threat of bushfires.
(Dr Ramsay) Well we need to get the message across
to people who don't believe that there is anything
that they can do in the face of a bushfire.
We need to get them to understand that there are
many things which they can do in building a new house
or improving their existing house, even small
things which will greatly improve the chances
of survival of their houses during a bushfire.
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