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.”
Jennifer Marohasy BSc PhD is a critical thinker with expertise in the scientific method.
Jen – Wood floors should be OK with insulation underneath them.
” Underfloor insulation
If you are building a new house, get two layers of foil draped over your floor joists before the floor is put down. This is remarkably cheap and effective insulation. If you are fitting insulation to an existing house, it’s worth noting that a small basement crawl space provides a significant – if not huge – amount of insulation. A single layer of foil under the joists – again very cheap – may be sufficient for you. If you have a big basement like I do, or an exposed floor, it’s worth looking at significant floor insulation. Foil-backed fibreglass blanket is the standard option, which is effective and fairly easy to install.
Another possibility is polystyrene, which can be slotted between the joists. Be aware that underfloor insulation may also reduce air leakage into your house, and so also reduce the amount of water getting into your house from the basement. These are additional advantages that make it a really worthwhile option. When I was half way through installing polystyrene under my floor, you could feel the difference in temperature between the insulated and uninsulated bits through the carpet! ”
http://www.xgl.com.au/pauls/home.html
I see no problem with plantation wooden floors. At least it is a renewable resource. Cement production releases a lot of GHG. Bamboo floors, if they could be a bit cheaper, are ideal.
jen – also this link
http://www.infolink.com.au/articles/F5/0C0285F5.aspx
I have lived in both and I can tell you heating and cooling on a tiled floor slab house is so much easier that a timber floor. Has that been factored into the equation?
There are also problems with ventilation, you need to keep some air movement to stop the musty smell. I have heard of the idea of underfloor insulation but have never seen it used, eever.
Unfortunately slab floors usually require cut and fill which then require retaining walls, more botheration and they aint cheap. On steep sites I have seen suspended conc floors with a polished finish, looks very trendy but you need deep pockets.
My previous house had karri floors, rimu ceilings with exposed oregon beams and timber french doors and windows and the kitchen had a laminated hardwood bench tops. The cladding was also timber which was a nightmare to paint as it was a 2 storey house. A lot of work building that one.
I think project home developers also prefer slab floors because they are easier and cheaper than timber – that;s probably the main reason for the trend. Most houses in NSW VIC i’d imagine would be slab rather than timber, and that’s nothing to do with energy efficiency regulation.
Recent research undertaken by the CSIRO has
shown that Australia’s ‘green’ rating tools for
building design and construction do not adequately
take into account the choice of environmentally
friendly building materials such as wood.
The report on 27 environmental assessment tools
entitled ‘Technical Evaluation of Environmental
Assessment Rating Tools’ found that current
building assessment schemes do little to enhance
the use of wood in buildings, despite the
environmental advantages of wood products from
environmentally and sustainably managed forests.
(See http://www.fwprdc.org.au/content/pdfs/PN05.1019.pdf
for the report)
The key information here is;
“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.”
On a high quality site a well managed regrowth forest or plantation could deliver two floors within 62 years. Three floors if coppice growth is utilised.
So even the AGO’s findings are in error because they only compared the cement with one wooden floor, not two. The second floor will have actually absorbed CO2 to produce a net zero emission.
And if the quality hardwood floor lasts for 94 years then there will be a net carbon sink equal to a third floor.
A cement floor will only outperform a wooden floor in life cycle CO2 terms if the wood is grown in a painfully slothfull, incompetently and negligently run publicly owned forest where decay and fire damage actually exceeds the growth increment.
In any native forest that is even approaching best practice management, a cement floor will NEVER outperform a wooden floor.
The other issue is termites, with slabs there is a big problem keeping the termites out of the house – the pesticides used nowadays are quite weak and need constant monitoring. Damage to houses by vermin is not covered by insurance so it can be a nightmare. many houses now are using steel frames, they can be stronger and are not subject to vermin. Maintenance of vermin is an additional cost.
Houses on piers do not have quite the same problem, if properly constructed with ant caps the piers are ant proof and can also be visually inspected and any termite galleries treated.
I’m tempted to agree with your analysis Ian M, even though i don’t think that energy efficiency regulation is the main driver for the switch from timber to concrete (maybe it could be a driver for the switch back though).
Ignoring embodied energy for a sec: heating and cooling only make up about 13-15% of household energy greenhouse emissions, and even less if you were to consider car use as part of that calcuation (check AGO 1999 residential emissions study on their website if you like as a ref.)
Building fabric is not the be all and all of greenhouse emissions in the home.
Electric hot water is the big greenhouse problem in homes, ask anyone (that AGO study is a good place to start).
In coastal homes with mild climate (ie most people) whether or not you have an electric hot water system is more important than whether or not you have an (insulated) timber floor or concrete slab, provided the rest of the house design is sound.
Especially in mild coastal climates like Sydney and Brisbane.
Instead of attacking energy efficiency regs, the timber industry could be working with government postively to improve them.
Maybe it is easier (because they are used to it) for the timber industry to just campaign against regulation.
Maybe thats easier by earning the ire of the housing industry by working with govt to develop embodied energy controls as part of housing energy efficiency regulation.
The housing industry won’t accept embodied energy regulation any time soon methinks.
If EE regulation was removed all together, people would still be using concrete slab, so if the timber industry managed to overturn energy efficiency regs, it wouldn’t make much difference in the southern states.
For how long will the average suburban house be left standing?
A few points which may have been missed:
1. My floating timber floor is made from a thick Victorian ash veneer on timber from trees of ex-Malaysian rubber plantations. So the Australian timber industry is getting some money from exports to compensate.
2. Despite what rog says, as far as I am aware builders favour slab-on-ground because of the saving on brick courses and piers needed to raise a timber floor. As a house with a timber floor is somewhat higher it also needs extra external steps at back and front. In a holistic approach the offsetting embodied energy of all these components needs to be taken into account.
3. As far as termite attack through slab floors is concerned: hasn’t this been addressed by the new termite proof mesh which I think has now been mandated?
4. In Canberra’s winter cold I definitely prefer slab-on-ground. With a timber floor the underfloor area needs ventilation and it is much more expensive to insulate under a timber floor than it is to insulate a slab floor.
5. As long as the dictates of passive solar construction are followed in Canberra I am pretty sure that GHGs saved by lower winter heating costs will quickly outweigh the GHGs embodied in the concrete floor.
6. If thermal mass is required in a house of timber frame construction this can be provided by brick internal walls so the valid comparison for this feature is between the embodied energy of a brick wall cf a stud wall.
7. I don’t know what “the Victorian timber flooring market” encompasses. Does it include chipboard type flooring? Hardwood flooring is rather in the luxury category and its decline may be linked to cost and style changes rather than environmental correctness.
8. I would think complaint from the building industry is the biggest factor keeping environmental issues simplistic so as not to push up new house prices. From looking around Canberra, although the government mandates environmental issues, builders often only pay lip service to proper passive solar design and the result is an inferior product environmentally.
Can anyone give a compelling reason why the government should have regulations for “energy efficiency” in home design. Would it not be more efficient to allow the market to set the price for energy, and also for the building materials? If we expect the Gov’t to mandate for energy efficiency, the logical end point is Gov’t standardised housing. You know, “to each according to their needs” and all that.
Thinking about this again: may be the forestry industry is just “framing the debate” here.
If renewable resources are the criterion for environmental respectability, why aren’t you talking about houses of straw bale, rammed earth, etc. Surely these better fit the bill environmentally but are precluded from respectable consideration by economic interests more powerful than environmentalists. (BTW the AGO would seem to have really got things wrong here for straw bale construction because this could be harvested 62 times rather than 2 for timber as Ian Mott suggests!) Isn’t it really our society’s hard headed emphasis on inflexible fixed assets which are tradeable and inheritable, thereby entrenching power and money, which act to straitjacket our environmental options?
If we truly believe in the power of the market to cure all ills, surely the fraction of our capital tied up in unproductive house and land ownership should be minimised by the use of less prestigious building techniques. This would free up capital to be invested productively and may be even leave some over for environmental goals.
Alternatively instead of looking at individual houses, shouldn’t you be viewing housing at a community level. More emphasis on dense, apartment dominated centralized cities would use economies of scale to minimize energy costs for heating, cooling and also transport while freeing land to enable city dwellers to appreciate the beauties of nature and the worthwhile roles performed by the forestry industry. But then again this emphasis on such large-scale buildings would seem to favour the use of cement-based construction.
I completely agree with your comments about your house being ‘your choice’. Lots of people have different reasons for choosing different building materials and their choices should be respected.
Probably the main reason your house is cold in winter is lack of insulation and drafts. A modern wooden house would have sarking, wall and roof insulation and aluminium window frames. Modern aluminium windows have effective draft seals, but of course they never look as good as timber.
About five years ago, I built a holiday house on the mid north coast of NSW. Most houses in that area are brick veneer on slab construction because that’s what people like. I built my house with Hardiplank and elevated plywood flooring, all with steel framing. The elevated flooring was necessary because the ground level was below 2.5 AHD. Our little house has amazing thermal properties. In summer, it never gets very hot and cools down fast with the afternoon breeze. In winter, the low ceilings, insulation and lack of drafts make it very easy to warm.
Concrete slabs might have some thermal advantages in the colder areas but they can be very expensive on difficult sites. Ideally, the slab should be exposed for maximum heat transfer.A typical woollen carpet and foam underlay will reduce its effectiveness as a heat sink. If we are going to ban wooden floors, we should also ban floor coverings.
Long term, the biggest advantages of a raised timber floor will be,;
1. ease of lift and shift. If the new buyer doesnt like the 25 year old house he can bung it on a truck and build afresh. In some suburbs on the Brisbane bayside this tradeup comprises about 20% of the whole housing market. It is a mega pain in the butt to lift and shift a brick toilet on a cement slab.
2. Under the floor is the best place to put domestic water storage. Tanks can be dug-in, new pipes and pumps laid and easily inspected, and there is no compromise on existing useable space. And whether you like it or not, every house will have one before too long. It is a major pain in the butt digging under a cement slab to install a water tank and even harder conducting maintenance on it in situ.
Another advantage is that you can do much of the fabrication yourself, especially with Unipiers – too easy!
http://www.bluescopesteel.com.au/go/product/quika-floor
Rainwater tanks are now mandatory in many parts of NSW, the water is used for washing etc
http://www.wyongsc.nsw.gov.au/development/PDFs/Ecoinfo40.pdf
Putting the discussion of embodied energy aside for one second:
I think its also important to note that wooden floors are not banned by energy efficiency legislation.
You just need to think about the way you construct your house differently compared to if you are using a concrete floor – as fat wombat described.
I think the timber industry should work closely with architects, property developers, and sustainable housing assessors to communicate how to build a sustainable house with a wooden floor if they are concerned about the impact of such regulation on their sales. Constructively highlighting the embodied energy aspect is good too.
Energy efficient housing is possibly still a not well understood or implemented concept for many building designers.
In the absense of good understanding, the market might be gravitating towards the easiest solutions to sustainable housing (eg. brick and concrete bunkers with portholes for windows) instead of delivering a sustainable solution that also satisfies amenity and other considerations (eg perhaps a mainly timber home, well insulated, some brick and tile for thermal mass, large windows for good views and natural light but with performance glass in places to avoid heatloss in winter, and eaves to shade in summer)
Ender says
“I see no problem with plantation wooden floors. At least it is a renewable resource. Cement production releases a lot of GHG. Bamboo floors, if they could be a bit cheaper, are ideal.”
Ender is there anything in your life you enjoy without it triggering this AGW obsession of yours.
Why don’t you simply just do it. Go find a cave somewhere and live in the bloody thing. You’ll be happier and it will also stop you from telling the rest of us what is good or bad in our lives.
Seriously, you should have joined the priesthood because at least in a Godly religion (as against the one you practice now) you would have found some happiness in life instead of this mirthless existence you seem to endure.
Do you have bamboo floors?
Here’s something that won’t upset you. Our floors are recently laid recycled old timber. We didn’t have to cut down trees for it, but the electric saw must have used some electricity to cut’m into shape. Sorry!
The thought of someone like joe trying to use an electric saw scares me. You should stick to things without sharp edges joe, or ask a responsible adult to do it for you.
As far as sales go Steve, 90% new home buyers want slab, you have a level entry (no stairs), no messy visible foundations and its easy to tile. Plus much cheaper.
I’m hearing you rog.
As i said before, I reckon that it is consumer preference and cost rather than energy efficiency regulation that is the cause of the downturn in timber floor construction in VIC and NSW.
I was just saying though, that the timber industry is better off building relationships and sharing info, rather than getting some poli to sound off on the issue.
Energy Efficiency regulation does not ban timber floors, and I think the timber industry is on totally the wrong political track by criticising energy efficiency regulation in the way they have.
They would be better off being constructive in finding ways to help planners improve EE regulation, and communicate the merits of timber to building designers (you know, free market kinda activity) instead of politically trying to attack such regulation (which, if removed, would not result in people suddenly going back to timber floors).
I can appreciate the argument that timber floors are popular in QLD (at least for existing homes, not so sure about new homes), and there is concern that EE regulation will discourage their use. But it doesn’t have to be that way, and being political about the issue rather than constructive is pushing sh1t uphill, given that pretty much every State has energy efficiency housing regulation, the trend is to increasing stringency, and the Federal Government is also working to try and bring in a nationally consistent approach.
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.
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.”
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.
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 ?
“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?
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.
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 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?
please tell me which is the cheapest to put ;slab or timber ??? I need a definitive answer Thanks