Do zero energy homes make economic sense? Seminar
On Wednesday 17th March, I attended the event at University of Salford, where the efforts of zero energy homes in Australia was discussed by two visiting speakers. Dr Trivess Moore, a research fellow in the Sustainable Buildings Innovation Laboratory (SBiLab) at RMIT University and Dr Stephen Berry, the manager of the research node for low carbon living at the University of South Australia. Both speakers are members of the Sustainable Housing and Urban Studies Unit (SHUSU), a multiple award-winning research and consultancy unit based at University of Salford.
Dr Moore spoke first, outlining facts including the population of Australia as 24.5 million and that the average size of the 9.2 million dwellings is 220m², over 3 times larger than the UK average of around 70m². he added that the houses themselves were rather large and that the average household size in Australia was 2.6 people in 2011, considerably less than the 1911 figure of 4.5.
The housing sector in Australia is responsible for around 12% of total final energy consumption and 13% of Greenhouse Gas emissions which are projected to continue to rise. This is where the Nationwide House Energy Rating Scheme comes in. It is a computer simulation which calculates energy efficiency going from 0-10 (worst to best) stars- the current minimum requirement in Australia is 6 but the average for any buildings built pre-1990 is 0!
The zero-energy housing project that ran included plans for 80 houses with energy efficiency of 6-10 stars. Through life analysis of the plans, it saw that for an 8 star zero energy home there would be an average increase of 7.8% on the upfront cost, which works out at around $31,000 AUD from average house prices figures but from the pilot study of 4 low energy homes and 7 control homes, the results were clear to see. On average the LEH households purchased 62% less electricity, 3% less gas and 28% less water compared to the department standard. This led to an average estimated saving for tenants of $1,050/ year, subject to changes in price of utility bills.
Dr Berry then took over to talk about his work on the Lochiel Park Green Village, a designated area of low energy homes designed and built to be minimum 7.5 stars on the Nationwide House Energy Rating Scheme. The buildings fitted in with the national averages for size, number of bedrooms and number of inhabitants and results showed the houses annual energy usage to be around ¼ of the Australian average in 2010-2011. He repeated the same concerns as mentioned by Dr Moore about the initial costs being more, but then showed figures with benefit/cost ratios of 2.52 in economic benefit to the owner.
Both projects have proven how successful low carbon living can be, there were examples in Lochiel Park of full self-sufficiency energy wise and even one house who was selling electricity to the local grid as they produced more than they used. Both speakers were extremely passionate and proud of the work they have done and I hope that we can incorporate some of the work they have done into housing designs in this country as the benefits massively outweigh the initial extra cost in construction.
For more information about the work being done visit: http://www.salford.ac.uk/sustainable-housing-and-urban-studies-unit