By Lyn Drummond
29 February 2012 – Australia’s housing sector has been ignored in the nation’s carbon abatement schemes despite representing a large consumption of energy and generation of carbon dioxide emissions, according to a new study.
One of the authors, Peter Newton, research professor in sustainable urbanism at Swinburne, said the focus for housing in the future needed to be on embodied energy as operating energy efficiency improved.
Dr Newton, formerly chief research scientist at the CSIRO, where he directed research on sustainable built environments, co-authored the paper, Pathways to Decarbonising the Housing Sector: A Scenario Analysis,with former CSIRO colleague, Selwyn Tucker.
The study concentrates on detached housing since this represents about three-quarters of the current national housing stock and 70 per cent of new residential construction, (Australian Bureau of Statistics 2008), Newton told The Fifth Estate during an interview this week.
Newton and Tucker decry in the paper that Australia’s housing sector, comprising over 7 million dwellings and their occupants, currently has no consistent or clearly defined role in the nation’s carbon abatement schemes.
This is despite the sector being a major emitter of greenhouse gases, estimated to be more than 10 per cent of the national total.
This effectively removes a significant incentive for innovation in green building, distributed renewable energy generation and energy efficiency initiatives, locking in poor performance of dwellings and wasteful behaviour by households, the paper says.
Key finding in the paper, says Newton, is that embodied energy has not received a great deal of scrutiny, given government’s principal focus on operating energy efficiency of new dwellings.
For instance, building owners were generally not aware of inputs into a building product, Newton told The Fifth Estate.
“For example, how much energy does it take it create a roofing tile, a double or single glazed window …….there are literally hundreds of different building elements all with an energy and carbon signature attached to them?”
Both the CSIRO and RMIT have done extensive work on embodied energy. CSIRO has found that the average household contains about 1000 gigajoules of energy embodied in the materials used in its construction. This is equivalent to about 15 years of normal operational energy use.
- See Your Home
- See this discussion of embodied and operational energy
- Articles on the Building Product Inventory Life Cycle Analysis in The Fifth Estate
The paper identifies pathways to a low carbon housing future through a new class of hybrid building (energy efficient shell, energy efficient built-in appliances and local energy generation linked to a national grid).
Published in Building Research and Information 2011, the paper demonstrates that hybrid buildings can achieve zero carbon status through combined lower energy consumption and local energy generation, achieving reductions in emissions of about 11 tonnes of CO2 for each dwelling per year, compared to new 5-star energy rated project homes (the current building standard) which generate on average 9.5 tonnes of CO2 emissions per year. The path to zero carbon for 5 star project homes with local renewable energy is now clear.
The paper also highlights key transitions in hot water heating, space heating and cooling, built-in appliances and plug-in appliances that can significantly reduce domestic carbon footprints in Australia.
Newton told The Fifth Estate: “We won’t get to zero carbon without drawing on renewable energy. In the short term, the best way towards decarbonising housing is tapping into the building scale or precinct scale distributed (local) energy generation.
“Each sector of industry in Australia should identify a pathway to reduce its carbon signature,” he says.
Energy efficient, carbon efficient, built-in appliances were needed he said – those that will last for a long time. Heating and cooling systems, hot water systems, lighting systems and kitchen appliances should become part of a building code in terms of performances, Newton says.
“Energy efficient plug in appliances can’t be regulated in the same way via building codes. There needs to be an energy standard associated with each appliance, some white goods have ratings such as a refrigerator, washing machine, but many don’t.
“There is no reason why they couldn’t all be rated, it is important to know what the energy performance is of anything that is purchased, like buying processed food, you need to know what ingredients it has.”
There was also a need to supplement conventional energy with renewables. Local energy generation was possible at a building scale or at a precinct scale, with wind, ground source heat pumps, fuel cells or combined heating and cooling power system, he says.
The Newton/Tucker paper says Australia’s housing sector has failed to sustain any significant initiatives in the carbon reduction process since the introduction of the energy rating scheme for new homes in 2003, even though the residential sector consumes 12 per cent of the total energy used in Australia (Sandu and Petchey, 2009).
Modelling of future trends in residential energy consumption has also indicated a likely increase of about 0.7 per cent of energy each year to 2020 (DEWHA, 2008).
By way of contrast, government initiatives in several other countries have aggressively targeted the housing sector for a major reduction in its carbon emissions.
For example, in the UK, new housing is to be zero carbon by 2016 (Department for Communities and Local Government, UK, 2006); in the Netherlands, 50 per cent of new housing to be (net) zero energy by 2016 (International Council for Building, 2009); and in California, all new homes to be zero net energy by 2020 (Marsden Jacobs Associates, 2009).
Plug-in appliances consume a substantial proportion of energy used in operating a dwelling, ranging from about 10 per cent for a 5-star dwelling to over 30 per cent for a 7-star dwelling. This confirms the finding by Lowe (2007), says Newton, that as efficiencies in the building shell increase, the relative share of a dwelling’s operating energy due to appliances will tend to increase, throwing a spotlight on this area as a focus of attention for further energy efficiency and GHG reduction.
Plug-in appliances also represent the class of energy use with a high growth forecast (Department of the Environment, Water, Heritage and the Arts 2008), particularly televisions, computers and standby energy.