I conduct energy and emissions assessments professionally and the claim that a carbon price will cause house prices to rise by $6000 is crap.

As a carbon consultant, I  have done several studies on the embodied carbon emissions of housing. I can say that embodied CO2e emissions from a double brick — iron house in WA are 0.51 — 0.55 t CO2 e per square metre (two-storey houses are in the higher end of this range). That is CO2 from all processes and components involved in building  a new house and landscaping package (see table),   Furniture and contents are not included as they are not part of a house and land package.

For an average four-bedroom house (185-square metre lockable area plus garage, alfrescoes and landscaping)  this computes to to 0.53*185 = 98.05 t CO2e. At a carbon price of $23 per tonne the “carbon cost” comes to $2255.

So unless there is some pretty serious price gouging (and government assures us they will ensure this doesn’t happen), the $6000 figure is a 2.66 times over-statement of the truth. I challenge the Housing Industry Association, Liberal politicians and others making that claim to substantiate their figures or at least divulge their sources.

My studies were conducted in depth. Emissions from construction and administration are from assessments of building companies using Department of Climate Change emission factors, WA electricity and WA gas and transport fuels all of which are similar for the whole of Australia. CO2 emissions for steel and concrete are from industry publications.  Other sources used were:

Alcorn, JA and Baird, G. Embodied energy analysis of New Zealand building Materials — methods and results. Victoria University of Wellington, Wellington, New Zealand CSIRO; University of Sydney, 2005. Balancing Act, a Triple Bottom
Line Analysis of the Australian Economy
.

Lawson, B. 1996 Building Materials Energy and the Environment.

Energy Strategies, 2007. Review of CO2-e Emissions from Concrete versus Timber Sleepers.

Pullen, S, 2000. Energy used in the construction and operation of  houses. Architectural Science Review.

The approximate breakdown of emissions is shown in this table.

COMPONENT % total embodied CO2e
House shell 48.7%
Other materials 12.3%
Administration and supervision 5.2%
Construction 8.7%
Transport 1.8%
Garage shell 10.0%
Veranda, balcony alfresco 3.2%
Fittings, fixtures 6.3%
Paving, fences, landscaping, garden 3.9%
TOTAL 100%

Another way of estimating emissions from housing is by using published embodied energy figures and then applying a CO2 emission factor. Sources cite figures for embodied energy of housing, which vary mainly because some only apply to the house shell, others to fitted and painted houses and others to the whole home/garage/landscaping package.

Some figures cited in the literature are:

  • Pullen, 2000.  Energy used in the construction and operation of houses cites an average of 5.9 GJ/sq m for 25 houses.
  • D’Cruz, N, 1990 cited values 4.3 – 5.3 GJ/sq m for brick and tile housing in WA.

My studies include the whole home/garage/landscaping package and estimate that embodied energy of Australian housing averages about 5.23 GJ/ sq m per sq m of lockable building area, Applying a generic CO2 emission factor of 0.092 kgCO2/ MJ (from my paper below, published on my website and reviewed by many readers) we arrive at a figure of 0.092 * 5.23 = 0.48 kgCO2e/ sq m, which is very close to that previously stated.

For those who want to read more about embodied emissions of housing my paper, Rose, BJ, 2010. ‘Ghg-Energy Calc Background Paper’can be downloaded here. Housing is covered in Section 9, pp 39-41.

I am incensed by the unsubstantiated claims being made by some industry bodies and politicians about all aspects of the climate debate. Claims that are at best gross exaggerations or at worst downright lies are being printed as fact by some sections of the media.

For the carbon cost of a house to rise to $6000, the carbon price would have to rise to $62 per tonne CO2 while at the same time builders continue using the same fossil fuel-intensive materials and practices.

By using lightweight materials such as timber and fibro cement, emissions can already be halved. Builders and consumers will increasingly choose eco-friendly materials and there is no reason to expect that the carbon cost of a house will ever reach $6000.