Warren McLaren reports on the new wave of housing in Australia which aims to not contribute to climate change.
South Australia has a plan. And it's not one for the weak of knee. They've set themselves the goal of reducing their ecological footprint by 30 per cent by the time the calendar flips over to 2050. The state's Strategic Plan sets out a whole raft of milestones to chart their course to this destination, a swag of which apply to the built environment.
For example, by 2012, new South Australian dwellings should be able to show a drop in carbon emissions to 108 per cent of 1990 levels. One of the key tools being employed to affect this feat is a re-think and re-design of suburban housing.
Lochiel Park is the workshop for this bold experiment. Here, within the suburb of Campbelltown, less than 10 kilometres northeast of Adelaide's central business district, a green village of 100 homes is evolving. When completed it is estimated the village will demonstrate a 74 per cent reduction in operational greenhouse gas emissions for housing.
A pivotal element of the approach has been the Zero Carbon Challenge, whose brief to architects was to conceive a three bedroom dwelling with the express purpose of managing its operational energy (as well as the embodied energy bound up its construction materials) back to zero, for the life of the building. South Australia's Land Management Corporation (LMC) (now known as the Urban Redevelopment Authority) and the Integrated Design Commission (IDC) who partnered up to establish this design challenge have set a home's lifetime to be at least 50 years. Now, it might be worth arguing that half a century is a very short life compared to the age of many homes in, say, Europe, but let's save that discussion for another time.
Five entries comprised the finalist's tally for the Zero Carbon Challenge, with Collaborative Future being called not once, but twice, to the podium, to collect the Winner prize and the People's Choice Award. The team that makes up Collaborative Future is composed of Cundall, TS4 Architecture, Holdfast Construction, Eco Active, Urban Sustainable Landscapes, MLEI, WT Partnership, Acdev, Ken Long, and Brock Urban Projects.
Their joint thinking created a house with a 16-week construction time, a 7.5 Star rating, and net zero operational energy.
Zero energy, zero carbon, or zero emission are different prefixes all referring to roughly the same thing: a dwelling that generates the same amount of (renewable) energy on-site, as it consumes in one year. The South Australian example goes one step further and includes the energy used in sourcing materials and building the house.
Similar monikers include a calculation for the energy used in a building's subsequent deconstruction or demolition. Others factor in electricity transmission line energy losses, while yet others consider a building to have net zero energy use, if its electricity is sourced entirely from a renewable energy provider, like a distant solar or wind farm.
It is worth remembering that all of these variations also use the qualifier term "net". A net zero carbon building's construction and operation may actually consume energy, and create emissions. But its renewable energy generation exceeds any use of carbon dioxide or greenhouse gas equivalent power usage.
Whilst the dwelling at Lot 61 Mundy Mews, Lochiel Park will be South Australia's first official 'zero carbon' house, we'd be remiss in not observing other parallel endeavours.
For example, the Australian Zero Emission House (AusZEH) project has already constructed, a couple years back, an 8 Star demonstration home in the Laurimar community of Doreen, Victoria. In this case Australia's peak scientific research body, the CSIRO, partnered with Delfin-Lend Lease and Henley Property Group, to construct the home, which balances energy efficient design with renewable energy generation (a 6 kW solar photovoltaic array) and an energy management system developed by Latrobe University. Other AusZEH members included Sustainability Victoria, SP AusNet, Telstra and the Victorian Department of Human Services. The intention was to showcase "a home that completely offsets greenhouse gas (GHG) emissions associated with the consumption of energy from grid connected sources by the on-site production of energy from renewable sources on an annualised basis".
According to Dr Greg Foliente, Senior Principal Research Scientist & Group Leader, the AusZEH house was the first to have the life cycle carbon calculated (embodied carbon including the construction stage not just the materials and PVs in the house plus operating carbon from operating energy) and neutralised (the former by carbon offset on completion and the latter by on-site generation on an annualised basis)
At the time of the AusZEH launch in 2010, Dr Alex Wonhas, Director of CSIRO's Energy Transformed Flagship, was quoted as saying, "CSIRO scientists estimate that if all the new housing built in Australia between 2011 and 2020 were zero-emission houses, 63 million tons of greenhouse gas (GHG) emissions would be saved." Describing that figure in layperson terms, he observed: "This would be equivalent to taking all of Australia's private cars off the road for two years and 237 days, or closing all Australia's power stations for up to 100 days."
In another 'zero is hero' collaboration, University of Melbourne's Energy Research Institute formed a team with Beyond Zero Emissions for their Zero Carbon Australia (ZCA) Project. Their endeavour of a "Transition to Sustainable Housing" has as a primary goal to "demonstrate that there are no technical barriers to zero emission buildings in Australia." And unlike many similar sounding projects ZCA are eyeing not only new buildings, but also retrofitting our existing housing stock, which they estimate to be about 8.2 million houses.
But zero emissions homes are not the sole domain of big name architects and research institutes. Peter Reefman is director of Energised Homes, a small energy efficiency company operating from the country town of Portland, in coastal Victoria. Peter built an 8.1 Star zero emission family home to demonstrate his work. The majority of the power used to erect the $405,000, two storey 213 sqm house, on an 800 sqm block, was derived from a local wind farm. The house was initially fitted with a 1.4 kWh grid connected solar array, whose Feed-in-Tariff income of about $800 per annum, more than compensates for the estimated heating/cooling costs of less than $20 per year.
Peter calculates that proper eco-design of his home allows it to, "operate with zero carbon emissions, water independence, as well as costing approximately $2,400 per year less to occupy than an average Australian house of the same size." He has figured that his return on investment (ROI) is conservatively about 16-17 years, but with rising electricity prices and the long term impact of national carbon pricing that this ROI can only improve.
Interestingly, Peter Reefman's conclusion from his home grown 8.1 Star zero emissions case study house is that, "7-Stars with efficient appliances, renewable energy, etc. is a more realistic and achievable way to the same end goal of zero-impact housing." Furthermore he believes that his home doesn't so much as replace existing building systems as improve upon them. Therefore the traditional housing estate style building industry should be well placed to construct carbon zero and sustainable housing for less than $250,000.
The aforementioned South Australian Zero Carbon House would suggest that Peter Reefman may not be too far off the mark.
Collaborative Future's $337,000 winning design achieves an annual energy saving approximating 70 per cent of what the average Aussie dwelling manages. This allows for minimal use of the Climate Wizard indirect evaporative air conditioning system and EcoSmart bioethanol (a.k.a. methylated spirits) heater. Such use is further offset by a 3kW solar photovolatic system that is said, will generate "more electricity annually than the house will ever use." The proof will soon be in the pudding as the house is due for completion before the end of 2012.
South Australia already leads the country in renewable energy generation, with about one third of Australia's solar power, and over half the nation's wind turbines, contributing more than one quarter of that state's electricity. If their Zero Carbon House strategy follows a similar trajectory they may well also lead the country in greener home design.
