Tone on Tuesday: On Bushfire Design

Now is not the time to discuss climate change and bushfires. The LNP federal government is right about that.

The right time was 25 years ago when the Labor party handed them the 6^th rated economy in the world. Now, though their ‘superior economic management’, it’s the 18^th rated. Debt and deficit, jobs and growth are all they want us to focus on.

Now is not the time to discuss climate change and bushfires, because if you never admit to the causes then it’s never going to be the right time to discuss taking any action. And if you ignore the link you can hope it goes away, and when it doesn’t it can be someone else’s problem.

With bushfire smoke in a ‘feedback loop’ increasing CO2 and making more drought, now is not the time to discuss climate change and bushfires. You’d have to understand a bit of science for that, and if you did you wouldn’t say that this is normal.

Given that scientists tell us that we should expect an increase in probability of bushfires, and an increase in the expected intensity of those fires, now is not the time to discuss climate change and bushfires, because it’s only going to get worse and we don’t have a plan.  

Now, with smoke fouling the air and doubling our CO2 annual output, is not the time to discuss climate change and bushfires. The rest of the world is already furious with our tricky climate change accounting. What if the extra CO₂ in bushfire smoke is not a ‘natural system’ and has to be offset by us doubling our efforts to reduce CO₂ output in other areas?

If we can’t discuss the causes, maybe we can discuss the effects, ameliorating bushfire by design. Which we can do in 3 ways: designing the bush, designing the buildings, designing the protection.

Designing the bush

The LNP’s approach is to say that the problem is with the bush itself: too much of it, too close, in the wrong place, not enough hazard reduction and so on. They would love to redesign the bush to make it, and the problem of climate change, go away.

Nationals in particular hate trees: ‘removing green tape’ is code for more and easier land clearing. They even equivocated when a Council Officer inspecting suspected illegal clearing was shot dead by a farmer.  More logging, (a favourite project of theirs with few jobs) is also seen as a way to reduce the problem. NSW now seeks to ‘privatise’ the forests, which can only open the door for more logging in more areas.

Bush clearing is another way of redesigning the bush: reducing or clearing parts of the bush to reduce fuel loads so fires are more easily contained and controlled. It hasn’t escaped attention that the wind speed and fire intensity this year simply ignored the good intentions and roared through cleared areas. It also ‘crowned out’ and jumped highways and crossed rivers where it had never done so before.

But ‘inadequate hazard reduction’ is the most common refrain trotted out in these bushfires. It’s a ‘look-over-there McGuffin’ that has the triple whammy of diverting attention away from the climate change connection, appeasing the mainstream media who need a villain, and providing an attack on the Greens and greenies (as if they were the same).

Hazard reduction refers to controlled burning of the bush in favourable times, such as winter, when deliberately lit fires can be managed to reduce fuel loads. However, despite the LNP’s complaints about inadequate hazard reductions, it turns out that the recommended levels were met before this year’s fires. But these recent intense bushfires were capable burning through areas that had been recently hazard reduced.

That trope is now defunct in two ways: similarly, to land clearing, it doesn’t always work during severe fires; and even if it did, it is increasingly difficult to do as the shorter and drier winters offer less opportunities for hazard reduction.

More pertinently it raises the conundrum of how to convince people who live in the bush to reduce the very the reason for being there in the first place. No point in a tree change with no trees.

In designing the bush for bush-dwellers we would be better served by looking to indigenous practices over thousands of years rather than the white man’s ways in 200 (and it is all men’s work).  We are learning from Bill Gammage and Bruce Pascoe that fire was a mechanism used by the indigenous to control and manage the landscape. It would pay great dividends to review those indigenous practices and learn from them before our usual caustic racism dismisses it.

Designing the buildings

Considerable work has been done in the last 25 years on developing codes, performance standards, and appropriate materials to resist bushfire attack. In the Building Code of Australia or BCA (within the re-badged National Construction Code or NCC) it is expressed as a Bushfire Attack Level or BAL. Technocrats love a TLA (three letter acronym).

A BAL ranges from low to high risk through a series of numerical steps culminating in the Flame Zone or FZ standing. The BCA is detailed in the design of buildings parts such as subfloors, floors, external walls, external glazed doors and windows, shutters and screens, roofs, eaves, flashings, gables, gutters and downpipes, verandas, decks, steps and landings, as well as the infrastructure of water, gas, electricity, and communications.

It's extraordinarily comprehensive, somewhat complicated and often 20-30 percent more expensive at the upper end. But the confounding part is that a building built to flame zone standard may still be burnt down given the intensity and ferocity of the current fires. Even the most stringent codes of design performance may be put to the test and found wanting in the most severe fires in the future.

In those severely exposed situations, a different form of building is required: the fireproof shelter. Often concrete and underground it is a "bunker" in which residents can seek refuge from the intensity of the flames whilst the fire is at its height. Recent Australian Building Codes Board (ABCB) advice governs the design of those shelters, for individuals or communities.

The documents all warn at the beginning that this is not a foolproof or a certain solution, always relying on solutions to tricky issues such as fresh air and oxygen supply and the exclusion of smoke.

As good as all this construction advice is, it only deals with new buildings. Given that we only add at most 2 percent new buildings to our building stock every year, if we were to change all of our design processes immediately to the highest standards, it would be 35 years before even 50 percent of the buildings were up to that standard. Clearly, an alternative approach is required, which is where protection comes in.

 Designing the protection

The most vexing question is designing bushfire protection for existing buildings. This is particularly so with heritage listed or venerated traditional buildings in towns and villages. As bad as the destruction of individual buildings was in Cobargo NSW, it is all the more distressing that as a suite of buildings they made an ensemble that provided the essence of the town.

The best form of protection for existing buildings is to install external sprinklers. In the same way that fire suppression inside buildings is by internal sprinklers (which are now mandated for all buildings over four floors) so they can be used to wet and suppress fire on the outside.

Sprinklers can be mounted discreetly on the outside of the building to protect key areas such as ridges, eaves, gutters, and windows and door glazing. The sprinklers may be automatically operated or manually controlled when the fire approaches.

A comprehensive code AS 5414 was developed in 2012 but has not been updated and has been criticised over some technical issues and for not addressing all BAL levels. There is also criticism that you pay for this Australian Standard ($140 approx. for AS 5414), as you do for all, when they should be free. That is for a later column.

The amounts of water required are considerable, between 400 and 1,000 litres/min. For a sprinkler system to work for an hour while a fire rages would require up to 60,000 litres in a water tank of say 6m in diameter and 2m tall. Collecting that water and keeping it clean and available is a considerable task given the drought.

Every building that owners want to protect should be able to do so, not just those of significance on the National Estate or a state register. It will be expensive, but an important part of the ongoing considerations in any future inquiry addressing the issue of the bushfires or a protection authority.

A dreadful parallel appears. When the last Labor government discovered that one third of all homes did not have roof insulation it introduced the much maligned ‘pink batts’ legislation. A worthy sustainable initiative dreadfully implemented. And one that would have helped in resisting a fire by the way.

Undeterred by that botched effort I would argue that a similar sprinkler initiative is needed. Only this time owners wanting a system (of sprinklers or shelter or both) would be engaged in the process, with subsidies or a loan from the government rather than a free donation.

We need better planning policies for bushfire. Better tree management based on indigenous principles, better building codes for all new buildings for more severe fires, but moreover our focus must be on existing buildings. Whether it is at the edge of towns, in villages, or deep in the bush we need to develop a way to store water in a dry drought ridden landscape, to drown the building when the fire comes.