Bushfire building codes burning your cash


Saturday May 24, 2014

Fire building codes burning your cash

By MATTHEW KELLY

March 3, 2013, 10:30 p.m.
  • RISK ASSESSMENT: Flames threaten homes in Garth Street, Edgeworth, last year.
RISK ASSESSMENT: Flames threaten homes in Garth Street, Edgeworth, last year.

A HUNTER-based bushfire management expert has challenged the need for stringent fire building codes to protect home owners  living  in low lying coastal areas.

Dr Christine Finlay said thousands of home owners in Lake Macquarie and Hawks Nest were being forced to spend thousands of dollars on fire protection measures  they did not need.

They include fire-proof fly screens, non-combustible window and door frames, and toughened glass.

‘‘These sorts of protective measures can add about $30,000 to the cost of building a home but they simply are not needed here,’’ said Dr Finlay, who completed a PhD in bushfire management at the University of NSW.

Her argument rests on the fact that  flat, low lying land in coastal NSW is above near-surface groundwater, which prevents vegetation drying out and becoming fuel to feed a firestorm.

‘‘Wetland swamp mahogany forest does not have the same flame capacity as dry sclerophyll forests that grow in  areas  like Marysville and Kinglake in Victoria,’’ Dr Finlay said. "But people are forced to build homes to withstand catastrophes like those that hit drought stricken alpine bush in 2009.

Morisset resident Michael Smith said fire codes had required him to spend several thousand dollars extra on his new home, which is about 20metres from rainforest. The rainforest is 1 metre or less above a permanent water table and flanks a permanent creek.

‘‘I really can’t see how they justify making you put in things like metal fly screens and door frames,’’ he said.

NSW Rural Fire Service deputy commissioner Rob Rogers said development in NSW was governed by the Planning for Bush Fire Protection guidelines  2007. 

The guidelines use NSW-specific  vegetation  classifications that cover 17 categories of fuel to allow for the variety of vegetation  across the state. ‘‘The Planning for Bush Fire Protection guidelines have been established to help ensure the safety of people living in bushfire-prone areas,’’ he said. 

‘‘They are designed to ensure new homes are suitably protected from the potential impact of bush fires.’’

A Lake Macquarie City Council spokeswoman said all NSW councils were required to comply with the bushfire  guidelines.

She said they have been developed by the Rural Fire Service and Australian  Building  Codes Board.   


  • Dcevans  a year ago

    Why do we have local councils at all? 
    When we the rate payers are forced to pay extra for an inept system of local government that refuses to do its own research and simply treats as an absolute, guidelines put together as a general starting point for the whole of a state. 
    Once again the governmental burocracy, we have created in Australia, proves its worth.

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        Firey  a year ago

        Oh Dr.Finlay , I bet you have NEVER been on the frontline of a raging fire. The north west are of Lake Macquarie has been the scene , and overdue , for large fires. Mr Smith tou might be 20 meters from bush but do you know ember attcks can travel kilometers , indeeed years ago fires at Tingara Heights were started from embers from Cessnock. The people complaining about the codes obviously have not expierenced bushfire

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            James  Firey  a year ago

            Well Firey if I live in Charlestown and have to worry about damage from bushfires in Cessnock, I doubt the gradient of my backyard is going to make much difference when an ember lands on my roof!

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                Firey  James  a year ago

                gradient effects rate of spread of fire , for every +10 degrees it doubles , the opposite occurs for negative gradients

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                    Dr Finlay  Firey  a year ago

                    Hi again Firey
                    If an ember falls on a roof, most important  in assessing flame capacity is the surrounding bush's fuel. Vegetation is considered fuel if it is dry. This is the foremost principle of determining flame capacity, even if the RFS guidelines you defend so hotly do not say so. Flames from dry sclerophyll forest are the biggest risk around Newcastle and Lake Macquarie as has been evidenced in fires, not over the last decades, Firey, but over the last two centuries!!! In the last decades, fuel loads have never in history been higher, is this why you do not mention fuel loads but  quote statistics of gradient and rates of spread? If a surrounding fire is burning at high intensity, houses will superheat and when embers lodge in roofs, catch alight. I doubt that the general reader can understand what you said about negative gradient. For the readers' benefit, a negative gradient is when a fire burns downhill, which except for fire tornadoes and fire willy willies, will be a cooler fire than one burning uphill. Your statistics of slope are relevant Firey, but of secondary importance as a factor in calculating flame capacity. Because you do not mention fire tornadoes and fire willy willies, your statistics are also incomplete. A fire tornado travelled downhill (a negative gradient) to rip Canberra apart in 2003. It moved in from the NW from McArthurs Hut in the Brindabella Ranges. These destructive fires came from mountainous drought-stricken dry sclerophyll forest where the fuel loads were around 25 tonnes per hectare. A fire burning 5 tonnes per hectare or more of fuel is beyond firefighters' control once it starts spotting or blowing embers. Currently, epic firestorms have left inland mountainous forests with fuel of around 2,100 tonnes per hectare in vast tracts of totally dead ash trees. A mix of drought-stricken dry sclerophyll forest and mountain ash surrounded Kinglake and Marysville in 2009. But this is a totally different scenario  to the Morisset site with its permanently moist to boggy soil and bright green drought-proof vegetation under swamp mahoganies that never in the last two centuries presented as problem fires.

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                    Dr Finlay  Firey  a year ago

                    Hi there I have been on the frontline of a raging fire and in west Lake Macquarie too. This was in 2001 and the fire died down from a firestorm to manageable flames once it hit areas close to the lake above near-surface groundwater. Where it is above near-surface groundwater, northwest Lake Macquarie is drought-proof and its swamp mahogany vegetation has never in Australian bushfire history presented as a problem fire. Why make people build to withstand a Marysville style inferno?

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                      FG  a year ago

                      In Newcastle area, we are more concerned of house fires. Many of the houses are old and under maintained, electrical system is out dated and can't cope with new home appliances, especially during winter when electrical heaters are in use. Smoke alarms don't work properly, as many of the houses are exposed to outside temperature due to poor building material used or the owners don't check if they are still working and put the neighborhood in danger. Above all, electrical poles and lines hanging in the air should be installed under the ground. They pose great danger during lightning and strong wind.

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                          James  a year ago

                          The assessment you have to have done in order to work out what is required on your particular property is draconian, unduly complex, and very expensive (like over $1000 for a surveyor - you need one to estimate the slope if your place is not completely flat). 

                          And that can apply just for a back deck reno. I think they should have another look at these mad rules. 

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                              Firey  James  a year ago

                              Decks , especially timber , go up real quick in a fire , they have to be designed and constructed to prevent embers getting underneath. Back in 1994 , one of the townhouses in the complex on Charlestown Rd backing onto Raspberry Gully was gutted from a bushfire. People have short memories , building codes come about from the lessons learnt the hard way over decades

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                                  Dr Finlay  Firey  a year ago

                                  Hi there Firey
                                  That is correct decks need to be built to withstand the flame capacity that the site is capable of producing. The Morisset site has a low to moderate flame capacity, so houses should be constructed to the building code for withstanding low to moderate bushfires. Why spend unnecessary money on withstanding a flame intensity that the site's drought-proof, bright green vegetation has never in the last two centuries of history reached?

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                                      James  Firey  a year ago

                                      One townhouse in 20 years?  As FG says, around here we should be more worried about home maintenance, faulty electrics and neglected alarms. What are the stats, Firey since you are into numbers?

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                                      Dr Finlay  a year ago

                                      An alleged forest fire threat of the intensity of Marysville or Kinglake flanks Mr Smith's northern boundary. This threat is in reality rainforest around a permanent spring-fed creek with bright emerald green native bush mixed with escaped privet. Added to the buffering effects of the permanent creek and its lush, bright green vegetation, near-surface groundwater runs one to 0.3 metres below, keeping the clay soil perpetually moist like fresh icing on a chocolate cake. Even when NSW is in drought, the soil is wet as if it has just rained. There is no record of rainforest with bright green understorey fed by a creek and with its soil perpetually moistened by near-surface groundwater even burning. An inspection of the site found no scorch marks for a 100m radius of Mr Smith's property. About 700m to the west, were several sprinklings of scorch marks on swamp mahogany trunks in slightly different topography, where, as I state elsewhere in this blog, the flame capacity was low to moderate. There is no record in Australian bushfire databases of rainforest around a permanent stream and above near-surface groundwater burning. Yet Mr Smith has to build to withstand Marysville and Kinglake to meet his legal obligations.

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                                          Blackened Stump  a year ago

                                          Don't you just love how secondary authorities hide behind legislation?  And especially rules developed in Sydney by so-called government "experts"? " Protect your backside" was the catch cry when I served my brief time in the public service many moons ago.  "The real world" was acknowledged then to have the real experts, but not now.  Anyone protected by legislation is now the expert.  Protecting their backsides as the above article reveals. All that legislation in Victoria did didly squat at Kinglake.  Anything changed in the Blue Mountains?

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                                              Dr Finlay  Blackened Stump  a year ago

                                              Hi there Firey

                                              What happened to that ancient tradition of using a large body of evidence? During my PhD and later research I was on raging firelines - observing very closely. I have also done around 150 interviews - bushfire scientists, firefighters, victims, bureaucrats etc etc... I am not talking about a gully at Charlestown - why are you talking about it?  I am talking about an area in Morisset where the ground is permanently moist from permanent near surface groundwater between 0.3 to 1 metre below soil surface. The site's predominant vegetation is swamp mahogany, which has NEVER presented as a problem fire in any Australian bushfire database. The site's scorch marks are only on a few trees and 1-4 metres high, whjch translates to a low-medium flame capacity as corroborated by calculations using computerised adaptations of the McArthur fire Index, used to predict flame capacity. Extensive CSIRO research of flame capacity shows that the site's fuel is the permanently brilliantly green understorey of native grasses and bushes. Permanently bright green understoreys like this on ground that is permanently moist means construction built to withstand a moderate flame capacity is adequate. Permanent groundwater-fed streams flank the site's north, northwest and northeast. These streams feed into a floodplain with permanently moist soil, moist to the point of being like a runny mud pie in a wide band wrapping around the site's north, except when it rains a lot - the floodplain turns into a lake. But the RFS requires construction to withstand Marysville or Kinglake fires. Construction to withstand moderate flame capacity is a more than conservative estimate of the risk. There is absolutely no history of any bushfire damage or problem fires in the location.

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                                                Dr Finlay  a year ago

                                                Fixing the ever-worsening bushfire problem is paramount. Firestorms give the appearance of global warming, leaving vast rainshadows of blackened land that bring drought and hold heat because blackened land absorbs energy. Putting out the energy of one Hiroshima bomb about every two square kilometres, firestorms are hot enough to penetrate a layer cool air to cause heatwaves.  It was only in the 1920s that the mercury at Sydney's Observatory Hill weather station near the Opera House ever climbed into the 40s. It reached 40.6 and then 42.1 in February 1926 after January firestorms killed four in NSW. Then it moved into the 40s in 1929, 1930 etc etc after firestorms started. Now, when it gets above 40 at Observatory Hill, it is only after the start of a firestorm. If global warming was responsible, the temperature would go up first and firestorms follow.   Firestorms are making wild weather worse by putting around our national annual average of carbon particles into the air. Without protective clothing, a firestorm can kill you within minutes if you are 120m away. Before the 1920s, fires burnt cooler because fuel loads were low. Animals could escape and the bush's health improved. Seeds could germinate, scrub was cleared to allow more grass for animals to graze and alkaline ash neutralised acid soils. Cool burning and grazing to maintain low fuel loads buffers our drought, flood and heatwave pattern and bring gentle rain.
                                                 
                                                There is more than enough knowledge to stop catastrophes that do around $1billion in damage and cost upwards of $20million to fight. In the United States, there is the recently adopted forest restoration campaign. Historically, all our national parks and world heritage areas have practiced cool burning, grazing and/or conservation forestry. These successful US and Australian models need to be revisited and modified with new firefighting developments. There is a new fire suppressant called BlazeTamer that its developer says can put out firestorms. I have developed a strategy for BlazeTamer using Hercules aircraft costing a fraction of firefighting current costs if my guidelines are followed. Phil Cheney and David Packham’s technique of dropping incendiary devices from aircraft is also a vastly cheaper and easier way of making the bush safe with mosaic cool burns. All they needed was their encyclopaedic knowledge of fire and weather behaviour and a small fixed wing plane suitable for crop dusting.

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