Changes pave the way to carbon zero green star buildings.

Last week the Green Building Council of Australia (GBCA) announced updates to it’s requirements for green star buildings to drive the uptake of low carbon buildings. Also announcing two new versions of it’s green star rating after a period of industry consultation the GBCA’s head of market transformation, Jorge Chapa said:

‘While some of these changes are small, they will continue to build capacity and drive innovation in sustainable design and construction,’

Changes made to the Green Star include the following:

  • minimum requirements for greenhouse gas emissions for 5 and 6 Star Green Star buildings
  • measures to build industry capacity in air-tightness testing
  • a new materials pathway to incentivise the use of sustainably-sourced structural timber and
  • new requirements to enhance the health and well-being of construction workers.

Greenhouse gas emissions minimum requirements

Projects looking for 5 Green star certification are now required to achieve three Green Star points in the ‘Greenhouse Gas Emissions’ credit. They must also be 25% more efficient than a benchmark building. A building hoping to receive a 6 star Green building rating needs to achieve at least 6 points and show at least 40% efficiency above the benchmark.


“Our analysis has found that 95 per cent of Green Star-certified projects meet these criteria, so it’s not a big change at the moment. However, it sends a signal to the market that we are prioritising carbon. We expect to strengthen these requirements further over time,” Mr Chapa says.

Air-tightness testing

The ‘Commissioning and Tuning’ credit has been modified to accelerate the uptake of air-tightness testing. A new ‘Air Permeability Performance Testing’ requirement is also now part of a core component of the credit, contributing to the achievement of two points.

Companies such as Boon Edam have already introduced solutions to their revolving door offerings of a combination of horse hair and a Neoprene interlayer that reduces the air leakage by at least 30% and have already been incorporated into Green star projects such as the Rialto towers regeneration project in Melbourne.

‘The benefits of revolving doors are accepted worldwide, for both retaining warm air and cool air, which can be particularly important to the energy efficiency of HVAC plants in Australian and New Zealand buildings’ Said Michael Fisher MD of Boon Edam Australia

Structural timber

A new ‘prescriptive pathway’ for the use of structural timber aims to incentivise the material’s use. While the initial intention was to recognise engineered timber, such as Cross-Laminated Timber and glulam, after seeking industry feedback the scope of the credit was expanded to include all sustainably-sourced structural timber.

“We have always recognised the use of sustainably-sourced structural timber, but until now project teams needed to undertake a full lifecycle analysis to achieve Green Star points. This change makes it easier for project teams to gain points using responsibly-sourced timber, just the way we encourage the use of sustainable concrete and steel.”

Enhancing the workplaces of construction workers

The ‘Construction Environmental Management’ credit has been renamed ‘Responsible Construction Practices’, with a new point available for project teams that can demonstrate high quality staff support through health and well-being programs.

“Research has found the mental health of employees on construction sites does not meet that of other industries. This change to Green Star is about recognising that a building is not truly sustainable if it doesn’t look after the workers who constructed it,” Mr Chapa says.

Other small changes are being made to Green Star. New Innovation Challenges on Carbon Neutrality will be introduced in the coming weeks, while others are being rolled into existing credits; and loop holes are being removed that enable double counting.

Registrations under the legacy versions of the rating tools will be accepted until 30 September, after which time all projects will be registered under Green Star – Design & As Built v1.2 and Green Star – Interiors v1.2. Project teams working with legacy tools will be able to upgrade their Green Star submission on a credit-by-credit basis.

“As Green Star evolves, we continue to look for new ways to collaborate with the industry to find sustainable solutions. While we won’t compromise on the integrity of the rating system, we are flexible in how we work with project teams to get the best outcomes for industry and the environment,” Mr Chapa concludes.


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