16 May 2012 – If you are confused about the star ratings for buildings, a proposal on the table from the federal government might just sort it all out and bring the sustainability rating schemes into harmony, across types of ratings, between residential and commercial, and ramp the whole lot up to 10 stars for good measure.

These ideas, part of a proposal released on Monday only days after the budget’s axing of the Tax Breaks for Green Buildings program, seem to have taken the industry by surprise. But the ideas are a draft only and members of the working party that helped devise the framework say theu are not as radical as they might at first appear

The proposal, the National Building Energy Standard-Setting, Assessment and Rating Framework, is essentially a roadmap for the rebranded National Building Code, previously the Building Code of Australia.

Key questions raised in the framework include, should the star ratings of tools that might figure in minimum standards for the NBC such as NABERS and NatHers, go to 10 stars, where the measurement of emissions and so on would peter out to a neat zero?

Should NatHERS and NABERS be harmonised into one tool? Should they be related back to Green Star?

Should residential and commercial ratings be blended and expanded to include the energy consumption value of appliances?

Underscoring the framework are tougher minimum energy standards, marked as “x” in the document since they will be a matter for discussion.

Robin Mellon, Green Building Council of Australia executive director, advocacy and international, said that release of the draft on Monday had come as a surprise

“It’s been building up over a couple of years but the timing has taken us slightly by surprise.”

He had not had a chance to go through the document in detail as yet but said the GBCA would be speak to its members and put forward a submission.

However, there were no plans for Green Star to go to 10 stars, Mr Mellon said.

“It’s an industry rating tool, not a regulatory tool.”

The ratings were an “evolving benchmark,” he said and the top rating of six stars reflected world leadership.

“Six star green star is an evolving benchmark that represents a snapshot in time. It’s world leadership and world leadership in 2005 is very different to world leadership in 2012. If we were to abandon that and jump to 10 stars, that essentially rubbishes what’ we’ve said all along.”

WT Sustainability director Steve Hennessy said he had not yet examined the draft in fine detail but would likely put forward a submission to the framework on behalf of the Chartered Institution of Building Services Engineers.

One issue that concerned him was the suggestion to combine commercial and residential rating tools.

“The use of a common rating scale would simplify the communication of building ratings to the general public and improve understanding of the relative performance of different types of buildings,” the draft framework says.

“NatHERS uses a 10 star scale and NABERS Energy currently uses a six-star scale. The metrics underlying the scales are also different, for example the NatHERS scale uses a fixed end point (that is virtually no extra energy required for space heating and cooling a house) whereas NABERS Energy rates buildings against the performance range of existing buildings.”

But Mr Hennessy said that NABERS and NatHERS tools measured different things. It was like “comparing apples and oranges.”

The general public also did not generally need to understand NABERS since it was usually professional property people who needed to deal with NABERS.

The issue was puzzling, Mr Hennessy said. “We should have the debate and that’s fine.  It’s just that NABERS is accepted in the commercial property market. And the issue of going to 10 stars, I don’t see the point to be honest. But I can see with residential wanting to tighten that up”

Not so radical
PC Thomas, director of Team Catalyst and a member of the working party for the framework told The Fifth Estate that the proposals were not quite as radical as might first appear.

Much of the framework was directed at harmonising the modelling required in the various rating systems, such as for energy.

“What the consulting community and design community has been saying is we need to be using energy modelling for the BCA (now National Building Code) alternative verification method; we need to be using energy modelling for the energy credits for Green Star, and you also need modelling when you do a commitment for NABERS, that in the future the building will meet the NABERS rating, Mr Thomas said.

The problem was that many of the input data had been quite different.

“The client has to pay three separate sets of fees to do these models

so whatever bits can be commonly agreed to and if  we  harmonise those bits of data that feed in, the better.

“It’s not about getting a single rating.”

Some of the other elements that could be harmonised included inputs such as load requirements and what metabolic rate of heat production for people in offices would be used.

“It’s those kinds of things…. We’ve had a series of people looking at different standards and taking what can be considered common to all three [rating tools].”

In a covering letter that accompanied release of the draft framework, Gene McGlynn, framework committee chair and assistant secretary Building Energy Efficiency Branch said comment was particularly sought for:

  • whether every rating tool used for regulatory purposes should use a 10-star rating scale
  • whether there should be only one rating tool specified for compliance with building standards that require a minimum star rating (that is, whether it would be more beneficial to have only one house energy rating software tool that incorporates the best elements of the three existing software tools)
  • whether residential building standards should be harmonised across all jurisdictions
  • whether any changes to existing governance arrangements could improve the development and administration of rating tools used under the framework.

The framework is also accompanied by three additional reports:

  • An investigation of possible future increases in building standards by Pitt & Sherry
  • An examination of the implications of including on-site energy generation in building  standards by Energetics
  • A study of no or low cost redesign options to meet current or increased residential building standards by Sustainability House.

For all the documents see:

Deadline for comments is Friday, 6 July with consultation forums to be held in each capital city from the 24 May to 13 June 2012.

Following are highlights from the report

Key aims include:

  • increasingly stringent minimum building standards set over time for new buildings and renovations
  • coverage of all types of residential and commercial buildings, including new and existing buildings
  • inclusion of building equipment and services as well as the building envelope in energy efficiency ratings
  • improving the accuracy of building performance assessments and ratings through consistent measurement and reporting
  • encouraging innovation and flexibility to meet defined performance standards
  • increasing compatibility amongst rating tools used for existing and new buildings
  • inclusion of broader sustainability issues over time including the level of greenhouse gas emissions generated and water used by buildings
  • continuation of star ratings approach to communicating building performance
  • facilitating effective monitoring and compliance

Other potential changes flagged include:

  • Consistent rating methodology, including appropriate normalisation, to ensure that ratings are meaningful and buildings can be fairly compared around Australia.
  • A consistent 10-star rating scale that includes quantitative information about the building’s performance for all building types.
  • The climate data used in rating tools regularly updated to take account of predicted climate change around Australia.
  • Alignment between pre-construction/design ratings and post- occupancy/operational ratings.
  • Flexibility in achieving building standards
  • Poor thermal efficiency not to be offset by installing highly efficient appliances or zero emissions energy generation, given the long life of the building envelope.
  • Building standards to be applied in particular locations tailored to the local climatic conditions, particularly in locations that are subject to extreme hot or cold weather events