Buildings that wish to achieve a 6 Star Green Star rating for design and construction will need to be carbon neutral after 2021 if an overhaul of the Green Star rating program for buildings is adopted.

In its latest announcement, the Green Building Council of Australia (GBCA) has called for feedback on its proposed new Green Star for New Buildings rating tool which is envisaged to be released in May 2020.

If adopted, the new rating will replace the Green Star – Design and As Built rating at the end of 2021 following an eighteen month transition period during which projects will be able to be registered under either tool.

As outlined in a consultation paper, the new tool will differ from the existing Design and As-built ratings in five ways.

First, it will deliver a new definition of sustainable building based around eight new categories.

These expand on the existing focus of lower carbon emissions and incorporate concepts surrounding making a positive contribution toward improving people’s lives.

The proposed criteria include:

• responsible design and construction practices
• promoting the health and well-being of occupants
• being resilient to climate and other shocks
• making a positive contribution toward better buildings through lower carbon emissions, water consumption and impact of materials
• supporting the creation of safe, enjoyable and inclusive places
• encouraging solutions which promote the social health of people and the community
• encouraging connections between people and nature; and
• recognising projects which show leadership or set a strategic direction for the industry.

Second, the new rating will set more ambitious targets in respect of certified buildings.

Under these targets, buildings would have to achieve full carbon neutrality and be ‘net zero carbon’ in order to achieve a 6 star rating.

Buildings rated 5 stars would have to be ‘net zero ready’ whilst those rated 4 stars would need an energy performance level which exceeds minimum requirements of the National Construction Code.

The paper draws distinctions between the notions of ‘net zero carbon’ required for six stars and ‘net zero ready required’ for five stars.

In addition to having a transition plan to eliminate fossil fuels on site, for example, ‘net zero carbon’ buildings would have to minimise fossil fuel use, use no gas for electricity generation and offset the remainder of its greenhouse gas emissions.

Buildings which were merely ‘net-zero ready’, meanwhile, would simply have to have a transition plan to eliminate fossil fuels on site.

According to GBCA, these new targets will better align the built-asset sector with Australia’s commitments under the Paris Climate Accord. The new targets will also better align with GBCA’s carbon positive road map.

The third change will see all Green Star New Buildings certified ratings including those which achieve the 4 Star rating meet a defined set of ‘best practice’ standards based upon ten criteria.

These include withstanding climate-related risks, being at least ten percent more energy efficient compared with NCC 2019 requirements, having water efficient fixtures and appliance, being commissioned and tuned to operate optimally over time, environmentally friendly construction practices, monitoring of energy and water use, active transport facilities (bike racks, showers etc.), sustainability related information being transferred to owners at handover, better air/light/noise quality and minimisation of toxic chemicals.

Forth, to cater for different types of building, the new Green Star for New Buildings rating will contain a pool of credits which is available based on the type of building in question.

Hospital and healthcare facilities, for example, could earn credits through low toxic furniture, disposals of trade waste and inclusion of respite places for those who need them.

Industrial facilities, meanwhile, could earn credits through vehicle emission reductions and tenancy energy reduction programs.

Finally, two options are under consideration to enable projects which excel in certain areas to gain recognition for their efforts.

Under the first option, there would be a new program which recognises projects which excel on specific issues. This could allow GBCA to issue ‘badges’ for comprehensively addressing resilience, for example.

The second option would see a new rating level designed to push boundaries beyond six stars.

GBCA’s Head of Market Transformation Jorge Chapa said the Green Star rating system had transformed Australia’s built environment with the certification of more than 2,250 projects across the country since its introduction in 2003.

“Now, in consultation with industry, we want to build on this success and deliver the next generation of aspirational targets to ensure Australia’s built environment stays at the forefront of sustainability,” he said.

“The next critical decade needs ambitious actions.”

The new standard is part of broader changes to the Green Star rating systems.

Separate discussion papers exploring changes to Green Star – Communities and the Green Star certification process will be released later this year.

Consultation on the new rating is open until June 10.