Carbon zero buildings are coming: Green Building Council

Carbon zero buildings are coming: Green Building Council

7 July 2017

In its latest update to the Green Star rating tool, the Green Building Council of Australia (GBCA) has sent a signal to the market: carbon zero buildings are coming. After a lengthy industry consultation period, the GBCA has released new versions of the Green Star – Design & As Built and Green Star – Interiors rating tools which promise to drive the uptake of low-carbon buildings, incentivise new industries and challenge the market leaders to innovate.

Among the key changes to Green Star, are:

1. minimum requirements for greenhouse gas emissions for 5 and 6 Star Green Star buildings

2. measures to build industry capacity in air-tightness testing

3. a new materials pathway to incentivise the use of sustainably-sourced structural timber and

4. new requirements to enhance the health and wellbeing of construction workers.

“While some of these changes are small, they will continue to build capacity and drive innovation in sustainable design and construction,” says the GBCA’s Head of Market Transformation, Jorge Chapa.

Minimum requirements for greenhouse gas emissions

A project with 5 Star Green Star certification is now required to achieve three Green Star points in the ‘Greenhouse Gas Emissions’ credit, and be 25 per cent more efficient than a benchmark building. A 6 Star Green Star building must achieve a minimum of six points and demonstrate efficiency of almost 40 per cent 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

Changes to the ‘Commissioning and Tuning’ credit have been made to accelerate the uptake of air-tightness testing. A new ‘Air Permeability Performance Testing’ requirement is now part of a core component of the credit, contributing to the achievement of two points. “This is about building industry capacity and educating project teams about the value of air-tightness testing,” Mr Chapa explains.

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 wellbeing 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.