At the recent Timber Communities Australia national conference, prominent federal Labor politician Martin Ferguson called for a rethink of the national energy efficiency standards for residential buildings in Australia. He told conference delegates:
"Whilst we would all support practical measures that increase energy efficiency, it seems to me that the new building standards are underpinned by too many questionable assumptions and too little scientific evidence.
So does the Productivity Commission which reported its concerns about the analytical basis for the standards last October.
The key issue is the focus on reducing household energy running costs and the thermal performance of the building shell.
And, at least at the time the Productivity Commission was undertaking its investigations the Australian Greenhouse Office’s (AGO) home design manual noted that true low energy building design will consider embodied energy and take a broader life-cycle approach to energy assessment – merely looking at the energy used to operate the building is not really acceptable.
Because timber framed construction is lightweight in nature, it does not fit the thermal performance philosophy.
The analytical basis used also means that concrete slab-on-ground comes up trumps for efficiency over suspended timber flooring.Consequently, $70 million worth of sales a year have been lost in the Victorian timber flooring market since the Victorian rating system was introduced.
This is despite the fact that a 1999 study undertaken for the AGO found it would take 62 years to get a net greenhouse benefit from a concrete floor over a timber floor.
And recent research indicates a concrete slab produces a net increase in CO2 emissions of 15 tonnes per house compared to a timber floor.
The problem is the standards ignore the fact that cement is highly energy intensive to produce while timber is a renewable resource, grown using direct sunlight and processed using relatively little energy in sawmills.
And sometimes, the energy in sawmills is produced using biomass from wood waste itself.The Productivity Commission has recommended the Australian Building Codes Board commission an independent evaluation of energy efficiency standards to determine how effective they have been in reducing actual – not simulated – energy consumption and whether the financial benefits to individual producers and consumers have outweighed the associated costs.
And the sooner the government ensures this is done, the better because in the meantime the timber industry is suffering and it may well be doing so for no good reason.
I am pleased to see that the industry has successfully lobbied the Victorian government for an amnesty on wooden floors in new homes until April 2007 to allow time to address this issue.
But it is clear that the greens are now much more sophisticated in their attack on the forest industries, directly targeting industry markets to achieve their ends.
The Wilderness Society responded to the Victorian amnesty saying it was a “cynical attempt by the industry to maintain market share” rather than improve energy ratings or environmental sustainability."
My house is cold in winter, it is wooden, with old wooden floors. But its my choice and I can't understand why environmental groups don't support the Australian timber industry so other home owners can appreciate the beauty of wood... wooden floors, wooden furniture, wooden window frames. And as Martin Ferguson said at the conference:
"Australia has 164 million hectares of native forests – 4% of the world’s forests – and 1.7 million hectares of plantations.
About 10% of our native forests are managed for wood production with less than 1% being harvested in any one year. That small proportion of forests harvested annually is regenerated so that a perpetual supply of native hardwood and softwood is maintained in this country.
Australia’s rigorous forestry standard, the AFS, has global mutual recognition under the Programme for the Endorsement of Forest Certification, the largest international sustainability recognition framework for forestry in the world.
But the greens are running a duplicitous campaign around the globe to undermine the status of the standard."
please tell me which is the cheapest to put ;slab or timber ??? I need a definitive answer Thanks
The thermal mass issue is becoming more and more important with regard to timber frame/wondows/doors. Paricularly in the UK, where the concrete lobby is actually claiming that timber's low thermal mass (and the resulting cooling costs) mean concrete is actually an envionmentally friendlier material. Can anyone think of a good rebuttal to this?
Well put, disgruntled. But the real killer of the cement slab, in economic terms, is in the foreclosed options in 20 odd years.
At7% interest, the net present value of a dollar in 20 years time is $0.26. And this means that the cost variance today between a slab and a timber floor should not be more than 26% of the cost of lost opportunities in 20 years time.
But in fact, most new houses are built on 600 to 1000m2 blocks and the house is located in the middle of the block to maximise buffers between neighbours. And this effectively precludes the future subdivision of the block by empty nesters as part of their retirement stategy.
It also precludes a simple lift to add an understorey flat. The same trick with a slab requires the removal of the roof, reinforcing of walls to take the weight of an extra level, and possibly, augmenting the slab to take the extra weight.
Hence, the lost opportunity resulting from the slab is the value of an extra house block in 20 years time. At, say, $200,000 in todays value, that means the net present value of that lost block is 26% or $52,000.
A wooden floored house can be lifted and shifted sideways, or sold off-site, at a cost of about $10,000 to produce a net cost of slab of $42,000. Spread that cost over a floor area of 210m2 and it adds another $200 for each square metre of floor.
And that, folks, adds up to a bloody expensive floor. The best imported italian marble would be cheaper.
The notion that Government can improve a situation and impose a solution is a myth; Governments should confine their activities to ensuring that industry groups can act freely. The Wilderness Society is neither an industry body or a government body and is irrelevant.
Building codes should be confined to performance criteria only and not be corrupted by secondary issues that are not relevant to proper construction.
Globally Government has already demonstrated its almost total ineptitude in designing and constructing proper affordable housing and does not need to repeat the "solution" to prove the point.
"Instead of attacking energy efficiency regs, the timber industry could be working with government postively to improve them."
Couldn't one also say "instead of attacking industry employment and undermining useful use of timber materials, the government and Wilderness Society should be working with industry groups to improve them?
Neil - come off it - Abetz is just sucking upo to the constituency after gettng their votes. Good spruiking for the faithful. So where is the evidence of this vast ongoing international campaign against Australian timber?
This is the same government that has "knicked" the carbon rights of landholders in the land clearing debate but no additional votes in that is there.
And after AWB - treason - ha ! You don't seriously believe these guys do you ?
We had to use a slab due to height restrictions when we lifted this small house. I dislike the slab intensely-- Ian Mott is correct re the limitations imposed by the slab-- A few more--Because plumbing is encased in concrete, we can't easily get at it for either repairs, or modifications, or accessing the waste shower/laundry water. They also wrecked the natural runoff and good garden soil by cutting to level the slab area--Just witness the amount of levelling and soil removal which takes place on a large development site-- Furthermore, the slab prevents any inexpensive and natural storage areas 'under the house' especially on sloping blocks--Also, witness people moving into an 'average' new home, and for a while all sorts of paraphenalia
clutters the garage until storage sheds-areas are built (more expense).. and lets not forget the kids who have nowhere to do things except 'in the house'. Being queenslanders, we as children could do a great many things 'under the house' without being constantly underfoot, along with the family dog, dad's workshop, and wet weather drying areas. The slab is very cold in winter and I dont want carpets anymore.. I also notice the amount of dirt-mud trekked in by both people and dogs
is much greater than when I had a few steps in the previous house with compressed board flooring. I'm not convinced the slab is cheaper and it's certainly more restrictive. Various council restrictions prevent good energy design-- This house faces west, but the 20foot from the front boundary rule prevents us building shading in this very hot area;I believe there are 'horses for courses' but the 'one size fits all' mentality seems to reign in regulation land. So far I've had no luck shading it with sensible trees, the topsoil being sacrificed for slab preparation; the man made garden soil we purchased is really only sand base and doesn't hold moisture. I think many of the benefits touted by experts are more theoretical than people-friendly, admirably suiting those with more expensive lifestyles.
At the same conference, Federal Minister for Forestry, Senator Eric Abetz, suggested (http://www.mffc.gov.au/speeches/2006/timber_comm.html) that the actions of the Green movement and others in this area are akin to treason.
"Treasonous because by spreading lies overseas about our sustainable timber industry, the Green movement is actively campaigning against the interests of Australia and all Australians", and "… by spreading lies overseas about our sustainable timber industry, the Green movement are promoting the continued unsustainable and illegal harvesting of the world’s rainforests, and promoting the use of non-renewable and non-recyclable alternatives."
The biggest leg up to the timber floor industry could be if embodied energy was incorporated into energy efficiency regulation.
However, I think you'll find that the main opponents to having embodied energy regulation are in fact the housing and property industries, not the regulators, and campaigning so politically about a weakness in the regulation is a great way of playing into your opponents hands.
Imagine the embodied energy in building a World Tower or a Rialto Towers!!!!!!!
Can't imagine the concrete industry will be too thrilled with a move to look at embodied energy in regulation either.