15 April 2011 – Paul Banister was one of several respondents who put in submissions to the NABERS Energy review currently under way on whether the rating should be extended to more than five stars, and if so, how.

NABERS has come under fire from some quarters for inconsistencies, some of which it has addressed – in particular in the case of Victoria, where the tool was inconsistent with other states and territories.  See our coverage

Dr Bannister, managing director of Exergy Australia Pty Ltd, and an author of the methodology, said in his submission that he supported the extension of the scale to seven stars (from the current five)  “with the retention of the current scale between one and five stars, as far as possible” but he recommended changes to the original underlying methodology, of which he was a key author more than a decade when it first started life as the Australian Building Greenhouse Rating System or ABGR.

He said in the submission: “The recent exercise in Melbourne has demonstrated that alteration of the scales isn’t that much of a trauma to the market and so minor alterations should be considered, particularly if they don’t affect the top end of the scale too badly.

Paul Bannister

“However in its current form, the NABERS Office Energy tool is unsuitable for extension to seven stars because a zero emissions building in climates cooler than Sydney will have a positive benchmarking factor irrespective.”

He explained: “Going back a very long way when we put together the original ABGR, which is unaltered and which we have at the moment, we created corrections factors for things like climate and those were largely additive factors which means if you put a zero  emissions building in Melbourne into NABERS (which is generally a colder climate and uses coal fired energy) the building would come up with a non zero rating.

“When we developed the rating this didn’t matter. I remember saying to someone that this was not a problem but that, hey, that’s a problem we’d like to have, because the best buildings we had were four star [and because the problem manifested only at the higher star levels.]”

These  “end of scale issues” were “over the horizon” when this was developed. Now all of the other NABERS ratings such as for energy and water have used different methodology so this is not an issue.

“All of the tools other than offices work in different ways and so they don’t have that problem because we’ve learnt.”

Bannister says he’s been “agitating for quite a while” for some improvements.NABERS Energy works on a “normalised emissions” basis – it takes the buildings energy use and greenhouse emissions and then adjusts them for hours of use and location so that they are comparable with others.

In the submission he says:
“This means the underlying mechanisms associated with the climate, hours and occupancy mechanisms need to be corrected. Otherwise a seven star building will be impossible in Melbourne, for instance.

“This is not an issue for hotels or shopping centres as the methodology for these ratings does not suffer the same problem. The offices methodology needs to be brought into alignment with these ratings.”

He said tthe tenancy scale also needed to be better aligned across the country and currently “over-rates poor tenancies.”

“The review is an opportunity to fix these things and do them in a more coherent manner,” Mr Bannister told The Fifth Estate.

Some of the perceived problems with NABERS are not reasonable, he said.

“Some is real and some is blunderbuss. Things are changing in Green Star all the time. But NABERS probably hasn’t changed, the basic calculation has been static.”

Following are some details of the inquiry:

The NABERS National Administrator has been seeking submissions on a proposal to “future-proof” the NABERS Energy for Offices rating tool, by extending its traditional five-star rating scale.

A position paper canvassing industry views on extending the NABERS Energy for Offices rating scale to six or seven stars was released in November, exploring options to accommodate the next generation of sustainable buildings.
Position Paper: NABERS Energy for Offices – Future proofing the rating scale (96.0 Kb)

The position paper canvassed three options:

  • Recalibrating the current 5 star rating scale
  • Extend to 6 stars in early 2011, introducing the 7th star in the future as needed
  • Extend to 7 stars in early 2011.

Twenty-four submissions were received, and can be accessed from the site .

  • AMP Capital Investors
  • Australian Institute of Architects
  • Central Park Management
  • Charter Hall Pty Limited
  • City of Melbourne
  • City of Sydney
  • CitySwitch
  • Colliers International
  • D&E Air Conditioning
  • Energy Efficiency Council
  • Exergy Australia Pty Ltd
  • FMA Australia
  • Green Building Council of Australia
  • Hampton Sustainability
  • ING Real Estate Investment Management
  • Jones Lang LaSalle
  • Lend Lease
  • RICS Oceania
  • State Property Authority
  • Stockland
  • The GPT Group
  • WA Office of Energy Assessor comments
  • WA Office of Energy Industry comments

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