FIRE DOWN UNDER
by Philip Drew
New Scientist magazine (Vol. 204, No. 2728, 3 October 2009, p. 15) warns that projections for Australia indicate that while the country may avoid extreme temperature rises of 10 degrees centigrade as a consequence of world warming of 4 degrees C a Study by the UK Met Office suggests that, more alarmingly, the probability of "extreme fire danger days" per year when uncontrollable fires are likely to break out as a result of low humidity, strong winds and high temperatures will treble by 2050. David Karoly of the University of Melbourne who reviewed a range of wildfire projections concluded, "We are unleashing hell on Australia."
For something more than two centuries people have failed to adjust to the reality of Australian bush as a dangerous environment that requires special care and the design of settlements to defend against extreme fire events, preferring instead to see the bush as a pleasant green Arcadian landscape. Fire was not so much a threat in the UK, though it does considerable damage around the Mediterranean lands to the south, yet we persist in adapting both our architecture and the design of settlements as compact defensive enclaves in the bush. The following tentative series of suggestions for a new approach is offered to stimulate thought on how architects can contribute where the politicians and planners have left off, in thinking about creative practical solutions for fire survival designs.
Reconstruction after the Victorian bushfires
I am concerned that the bushfire devastated areas in Victoria will be reconstructed repeating the planning and building design mistakes of the past. It is understandable that the public should demand a rapid response by the Recovery Authority in view of the extreme shock and trauma suffered by the affected communities.
There are much better ways to combat extreme bushfire events and build-in defenses. The objective is to draw attention to the positive contribution offered by innovative design and imaginative planning measures to avoid repeats of Black Saturday in the future.
The talents of our best designers should be enlisted to develop outstanding innovative schemes for the rebuilding of the devastated communities by jointly sponsoring with the Victorian government an International Architectural Competition for the Reconstruction of Kinglake and Marysville in Victoria as two of the worst affected townships.
A new approach is called for given the likelihood that such extreme events will intensify in the immediate future. This requires new thinking and a radical reconsideration of how to plan rural settlements to survive extreme bushfires.
Bushfire -survival houses are not new, indeed, examples and the principles they embody such as built in external agricultural sprinkler systems and incombustible roofs and wall construction were being applied a quarter of a century ago in the early 1980s. Yet these innovative lessons were largely ignored by local government authorities. What was missing was the will to implement such advances.
I hope all the public agencies will now take notice of what must be a co-ordinated multi-pronged approach by Federal, State and Local governments authorities to adopt a newly revised flexible building code incorporating building practices and solutions that would ensure bushfire prone areas are safe, and limit dispersed isolated dwelling construction from locations where the danger is found to be too extreme for even the most fire safe houses to survive.
Consideration might be given to the following design principles:
CONCENTRATED SETTLEMENTS WITH A COMMON IN SITU FIRE SURVIVAL DEFENSE IN LIEU OF DISPERSED TOWNSHIPS
- This is based on the principle that it is more economical and effective in terms of resources to avoid dispersed housing in bushfire prone regions, and much cheaper in the long term to construct and maintain communal defenses bringing people together inside a common defense perimeter encircled by drenching sprinklers.
- Depth of defense so each house shelters its neighbour,
- A community water reservoir with automatic activation of sprinklers,
- Large common dugout with sufficient air volume to survive a firestorm and effective sealing to the outside.
- Such town design to include a rampart to deflect fireballs upwards much like blast deflection earthworks used for ammunition storage.
- A gathering point and alarm system.
- Fire Lookout.
- Fire control and organization HQ within the community shelter.
- Individual external sprinkler system to protect individual houses should the perimeter defense prove inadequate.
FIRE SURVIVAL DESIGN FOR SINGLE DISPERSED SINGLE DWELLINGS IN BUSHLAND
- A thorough scientific investigation of the most effective and economical architectural measures for surviving extreme bushfire conditions. Among these the BSDG recommends consideration of the following measures.
- Independent water drenching systems installed on the roof of dwellings that can be activated in under 5 minutes with their own independent water reservoir and pump system sufficient for 30 minutes.
- The adoption of fire proof materials outside which also are effective as radiant heat reflectors i.e., construction such as corrugated iron, insulation and masonry that reverses the usual practice of masonry on the outside and internal fire prone internal linings.
- Elevated dwellings to minimize the target area in the way of fire surges.
- Bathrooms designed as a secure wet refuges.
- Elimination of roof gutters and alternative rainwater disposal alternatives to maximize storage of water for firefighting purposes as well as potable use.
- Designs which employ inner courtyard planning supported by masonry fire protection within houses that can serve as fire retreat zones.
- Independent dugouts at each dwelling capable of accommodating 2 families and an air supply for 30 minutes.
- Consideration of dwelling locations to avoid sites of extreme bushfire intensity and alternative sites that have a low bushfire rating, thereby, to minimise the risk at the outset.
- Upgrading and consultative advice to house owners on how to best improve on the bushfire survivability of their dwellings.
- It is often difficult to obtain house insurance in bush locations. Consultation with insurance companies to encourage preferential policies and rates for dwellings which comply with the above principles.
I hope others will give serious consideration to the above suggestions prior to drawing up the Federal Government’s reconstruction plan for the devastated areas in Victoria, and also, you will think about their application more widely to other regions which so far have not suffered the same fate, but could do so, if intelligent action is not taken urgently to avoid such calamities. Do not hesitate to call or write if you are interested in discussing any of the above.