Australia has endured many calamities in recent times, with the country having weathered cyclones, floods, drought, bushfires and other natural tribulations.
Can Australia avoid catastrophe by improving resilience within the construction of buildings? Can revised standards of construction and the installation of disaster refuges make our buildings more resistant to extreme events? Can improvements reduce insurance premiums and improve survivability of extreme events?
The aim should initially be life safety, though protecting our built assets is a major concern. Extreme events and severe weather have been the cause of devastation and occasionally loss of life.
As land for development becomes scarcer, developments are more likely in flood prone areas where bushfires are a possibility, or on brown-field sites where toxic materials may be encountered. As people move increasingly to areas of natural beauty, including coastal areas, for a sea or tree change, it opens up risk that developments could be affected by extreme natural events.
Even as vast areas of the Australian continent are in drought, damaging floods cost the lives of five people in Caboolture. The damage bill for natural disasters are staggering, and they are only trending higher. As well as improvements to infrastructure such as flood mitigation, secure electricity and communications, what additional measures may be undertaken to mitigate the risks of catastrophic natural forces?
Australians are resourceful and robust people and it is amazing how often the spirit of rejuvenation allows communities to rebuild after a disaster. However, many remote areas, resorts and towns on the eastern seaboard and around the top end, do not have adequate flood and cyclone shelters. During cyclone Tracy, which hit Darwin in 1975, many lives were saved when people sought refuge in areas of their homes where there were core filled besser blocks – usually the laundry and wet areas under high set homes. The upper level of many residences were completely swept away. Should we consider ensuring all homes have a refuge for occupants from Northern NSW right across the top of Australia around to the Pilbara in WA, and also in bush fire prone areas?
Would compulsory fire and cyclone refuges save lives? The fact is, many of our regional settlements are vulnerable to bush fire and many individual houses and settlements are surrounded by volatile scrub and bush, where keeping the buildup of fuel controlled is difficult. The frequency of drought periods and times of high fire risk have increased and the ability to undertake controlled burn off of fuel buildup is restricted by the encroachment of residential areas and infrastructure which could be damaged during controlled burns.
In Queensland, the cost of natural disasters, flood, drought and cyclone can be shown to have a serious negative impact on the economy and lead to prolonged a painful downturn. The cost to South East Queensland of flooding over the past few years is over $10 billion.
Similarly, the cost of bushfires has had a negative impact on many states. In the Northern Territory, the people of the Warrumi community had to be evacuated in front of cyclone Nathan as there were no stormproof shelters. In Queensland, some remote communities and island resorts were also evacuated. Should all communities have refuges?
Could we include the provision of fire proof doors and fire shutters to ventilation in a refuge area of all residences in bushfire prone areas? A refuge as described would improved the chances of survival during cyclones and bushfires. As remote communities and resorts, mining villages should have a large enough refuge for all occupants and staff and enough water and supplies to independently survive for at least seven days before assistance arrives. After cyclone Yasi, food and essential medications were in short supply almost immediately.
One of the considerations when looking to improve the resistance of roofing materials to high winds is the type and number of fixings. Could a doubling up of the number of fixings improve the resistance of roofing as perhaps the lowest cost improvement in the resistance of dwellings to storm and cyclone damage? Cyclone rated roof fixings could be mandated in all areas and changes to upgrade current wind categories could improve resistance of buildings to storm damage.
Tiled roofs currently do not have a mandatory requirement for sarking. Good quality sarking which is continuous and taped has been shown to reduce fire risk, as small cinders during a bushfire can not readily get inside a loft space. Sarking also reduces storm damage when a tile is damaged or becomes loose, acting as a second barrier to water damage. Should sarking be made mandatory? That may be a relatively small additional cost for new homes.
As the current cost to insurance companies and in terms of infrastructure repair is running at well over $10 billion each and every year in Australia, it may be time to consider making our buildings more robust. House and contents insurance premiums are becoming unaffordable, especially in areas most likely to be impacted by severe natural events. The inability of residents and businesses to obtain building and contents insurance at reasonable premiums may well impact on the sustainability of many communities.