Buildings may soon be required to cut carbon emissions to 40 per cent below business as usual to qualify for a 6 Star Green Star rating, under sweeping changes now out for industry feedback.

The changes aim to start a conversation on major sustainability trends, including moving towards carbon neutral buildings, using engineered timbers, verification through air tightness testing and more sustainable site sheds.

The Green Building Council of Australia’s head of market transformation Jorge Chapa told The Fifth Estate the changes were a way of enabling the industry to “put its foot down” and say “a sustainable building should be this.”

“Sustainable buildings are the only ones that have real value to people,” he said.

The changes have been formulated over the past year, and involved contributions from between 60-70 industry stakeholders.

The GBCA is now calling for industry feedback on the draft proposals.

Mr Chapa said the COP21 discussions at Paris and their outcomes, including the GBCA joining the World Green Building Council in a commitment to drive carbon-neutral buildings, made the initial conversations easier.

Within the draft changes, new benchmarks have been set for carbon emissions reductions, with minimum requirements set for 5 Star Green Star and 6 Star Green Star.

“We are reprioritising carbon as a key environmental issue that our industry must address – and setting minimum requirements is an important part of this,” Mr Chapa said.

The benchmark for 4 Star is 10 per cent lower emissions than a “business as usual” building, Mr Chapa said. To rate as 5 Star, a building will need to be 25 per cent lower than BAU and achieve three credit points in the greenhouse gas emissions credit.

A 6 Star building will need to achieve six points in the greenhouse gas emissions credit category and be 40 per cent lower in emissions than BAU, and demonstrate it is well on the way to achieving world leadership in greenhouse gas mitigation.

“This measure would enable us to provide clearer differentiation between the star ratings, and to guarantee, as a minimum, that a 5 Star building would produce fewer greenhouse gas emissions than a 4 Star building, and so on,” Mr Chapa said.

Mr Chapa said there was also a broader plan to align Green Star with the distinct trajectories outlined in the Paris Agreement. The GBCA is currently working on a project that will outline its expectations for these trajectories and how industry can work towards them.

“It’s the roadmap that industry has been asking for.”

Engineered timber gets a smoother pathway

New provisions around engineered timber in the materials category will reduce the need for project teams to conduct a full lifecycle assessment to demonstrate materials including cross-laminated timber, laminated veneer lumber and glulam have a reduced environmental impact.

Mr Chapa said that because these materials are generally used in smaller projects, with smaller budgets, reducing the burden of documentation and complex LCA modelling for project teams would be a major plus.

He said the proposal also aims to support and grow the local engineered timber industry, with one point available specifically if the material is sourced or manufactured in Australia or New Zealand.

“Timber is a renewable resource, which combined with local sourcing, can contribute to job creation and skills development. This change to Green Star is about incentivising a new industry for engineered timber in Australia.”

Incentivising increased use of engineered timbers will have other benefits too, Mr Chapa said,

including faster construction, less workers required on site and less waste generated.

Major plus for multi-residential

Under a change to the commissioning and tuning credit, project teams will be encouraged to take up air tightness testing to demonstrate design goals around façade air tightness have been achieved.

Mr Chapa said this would likely have the most benefit in the multi-residential sector.

“Most unit owners have no control over improving the building envelope, unlike commercial buildings that tend to have just one owner and manager,” he said.

He said it was “unlikely” a commercial building would fail the test, however there have been ongoing concerns in the industry that multi-res is frequently not achieving its designed performance in terms of air leakage, which has major implications for thermal comfort, energy efficiency and occupant health.

“This isn’t about setting a standard for air-tightness yet, though this allows us to push Australia to take air-tightness seriously. This first step is about building industry capacity and educating project teams on the value of air-tightness testing.”

Mr Chapa said that if the change goes ahead, the GBCA will analyse and share the data gathered as a result to better understand “where Australian buildings are landing”.

This will then enable the GBCA and the broader industry to take action to ensure testing and standards for air-tightness are appropriate for Australian climactic conditions.

Sustainable site sheds

Greening site sheds and making them better environments for teams will be tackled under a proposed requirement within the “construction and environmental management” credit.

“This recognises a general shift within industry that high-performing, sustainable buildings demand site offices that meet basic standards of health and wellbeing,” Mr Chapa said.

The credit builds on the work of Multiplex, which has created sustainable site spaces under the Green Star Innovation Challenge.

Now everyone will be encouraged to do the same.

The new credit will also ensure all contractors receive sustainability training in addition to mandatory workplace health and safety training.

“We want to enhance industry’s understanding that sustainability is as non-negotiable as safety,” Mr Chapa said.

There are a number of other proposed changes, however Mr Chapa said these four would have the biggest positive impact.

“It’s over to industry now to provide feedback as we work together to create healthy, resilient and positive places for people and the natural environment.”

The consultation period on the draft Green Star updates is open until 27 January.

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  1. For more than two decades improvements in annual refrigeration plant energy efficiency from 15% to 70% have been reported by switching from synthetic to natural refrigerants and by introducing other energy efficiency engineering techniques at the same time.

    These improvements have been described in peer reviewed technical papers published by IIR/IIF (Gustav Lorentzen conferences for natural refrigerants), by AIRAH and by IIAR (International Institute of Ammonia Refrigeration).

    At the heart of the vast majority of air conditioning systems there is a refrigeration system.

    Perhaps the air conditioning industry will now finally have no other choice, but to consider natural refrigerants if the objective is to reach six star ratings in commercial buildings.