NABERS is the industry standard for ensuring the environmental performance of Australian buildings. It uses operational data to rate a building’s actual impact, rather than modeled design performance.

The NABERS tools were developed to help building owners and tenants reduce environmental impacts and costs by rating a building’s performance compared to other buildings on a five star scale. On this scale, 2.5 stars represented market average performance, and 5 stars was an aspirational target that had not yet been achieved.

After more than 10 years in operation, NABERS ratings are used throughout the property sector and in government policies and programs to drive measurable cuts in environmental impacts. Technology and management practices in the building sector have improved greatly and approximately 5% of rated buildings are now achieving 5 star NABERS Energy ratings.

The ultimate purpose of NABERS is to drive improved environmental performance. To ensure that NABERS continues to offer an aspirational target and to drive innovation and environmental improvement, a 6th star is being added to theexisting rating scale. A 6 star building will be considered ‘market leading’.

Eight office buildings will have their current NABERS Energy or Water rating upgraded to 6 stars to reflect their market leading performance and efficiency. A further twenty four office buildings have achieved 5.5 stars through efficiency alone.Twenty five office buildings have sufficiently reduced their greenhouse gas emissions or potable water consumption through the purchase of renewable GreenPower or recycled water to earn a5.5 or 6 star rating. Thirty three office tenancies, hotels and shopping centres have also received 5.5 or 6 star NABERS Energy or Water ratings.

The new rating scale:
0 .................... Very poor
1 .................... Poor
2 .................... Below average
2.5 to 3 ........... Average
4 .................... Good
5 .................... Excellent
6 .................... Market leading

How will the extension affect existing ratings?
The existing 0 to 5 rating levels will not change. All buildings currently rated at 5 stars that are performing at a 5.5 or 6 star level will be issuednew certificates eflecting their new rating. This will affect 80 existing ratings. Other current ratings will not change, and the meaning of those ratings will also remain the same. All future ratings will have the potential to achieve 6 stars.

How has the 6 star rating been calculated?

The first step in extending the rating scale was to set an upper limit of optimal building performance. For example, for a NABERS Energy rating,optimal performance is zero carbon emissions, and for NABERS Water, it is zero potable water consumption. The rating scale was then extended to reach optimal performance, which occurred at a hypothetical 7 star point. The 6 star level is set halfway between 5 and zero emissions/potable water consumption.

For NABERS Energy, the 5.5 and 6 stars are calculated by applying a fixed reduction in the percentage of actual greenhouse gas emissions from the existing 5 star benchmark. The 6 star rating represents a 50% reduction in greenhouse gas emissions from the 5 star benchmark (and 5.5 stars is a 25% reduction). This is explained in more detail in a Technical Fact Sheet that will be made available on the NABERS website.

Note that while a climate correction is currently applied to ratings from 0 to 5 stars, no climate correction will be applied to ratings above 5 stars.This is because the highest performing buildings are generally designed to be climate-independent.

This expansion methodology will be applied consistently across the suite of NABERS tools including hotels and shopping centres. For more information on the technical details refer to the Technical Fact Sheet available on the NABERS website.

Are all the NABERS tools changing?

The rating scales for NABERS Energy and Water tools for offices, hotels and shopping centresare being extended to 6 stars now, with 6 stars representing market leading performance. The existing five star scale for each tool will not change. The rating scales for NABERS Waste and Indoor Environment and NABERS tools for homes will be extended by mid 2012.

Has industry been consulted?

A position paper was released on the 23 November 2010 and comments were received over a 12 weekperiod. Twenty three stakeholder submissions were received, with 20 expressing support for the expansion. The submissions can be viewed on the NABERS website. The NABERS StakeholderAdvisory Committee, comprising a wide range of peak industry bodies from across the property sector, has also been consulted, and has providedadvice throughout this process.

What are the next steps for NABERS?

Extending the scale to 6 stars is an important part of the ongoing quality assurance and strategic review process for NABERS. The release of the 6 star ratingnow will enable NABERS to recognise current market best practice, and to offer an aspirational target.

Over the next 2 years, the NABERS office tool calculation methodology and benchmarks will be modified to work the same way as the hotel and shopping centre tools, aligning the suite of tools. Once this is completed, it will be possible to use the NABERS tools together to rate a multi-use building with any combination of these functions. As part of this project, the rating scale will be reviewed again, with a view to potentially incorporating recognition of zero emissions performance.

NABERS will undertake formal consultation with industry over the next two years to progress this important project.

Concern about climate change is driving rapid changes in the property industry, which is adopting new technologies and supply agreements for low emission energy and recycled water. The NABERS National Administrator (NSW Office of Environmentand Heritage) is also undertaking a strategic review of NABERS to consider how to highlight and reward the use of these low emission, low impact innovations. Key industry representatives and experts will be invited to join technical advisory groups to provide direction to this process.

Why 6 stars? Why not 7?

The 6th star has been released at this time to recognise the advances made in building energy efficiency in recent years and to provide an aspirational target that drives innovation. The inclusion of a 6th star will also enable upgrading the ratings of buildings whose environmental performance currently exceeds 5 stars. Only the 6th star has been released at this time as it is unrealistic for most buildings to achieve zero emissions or 7 stars. Future moves to extend the rating scale to recognise zero emission buildings will be considered as part of the development of a multiuse tool and will be subject to further consultations with industry and governments over the next two years, and broader policy developments that impact building rating tools nationally.