Construction industry's pathway to net zero by 2040

Researchers from UNSW Sydney have developed an online resource that provides a pathway to achieving ‘whole of life’ net zero carbon for Australian buildings by 2040.

Race to Net Zero Carbon: A Climate Emergency Guide for New and Existing Buildings in Australia is a 40-page guide which details critical information about materials and construction best practices to help architects, engineers and planners transform the building industry towards net zero carbon buildings.

The world’s built environment is responsible for 37% of global energy-related greenhouse gas emissions. In Australia, it is responsible for one-fifth of all our emissions.

Carbon emissions within the built environment occur across all stages of a building’s life cycle.

“Our guide draws on Australian climate data but has global applicability,” said Professor Deo Prasad, who is lead researcher of the guide.

“Historically, most professionals have only focused on reducing the operational carbon footprints of buildings. Operational carbon refers to what is required for the building to run once it is built, like energy use in heating or cooling.”

Operationally carbon-friendly buildings are fully powered from on-site and off-site renewables, which offset the buildings’ carbon emissions.

Meanwhile, embodied carbon footprints, which are accrued before a building is even constructed, have usually been overlooked by the industry.

“There are significant amounts of emissions embedded in the materials and construction of the building itself and these need to be addressed and offset in order for our built environment to be truly net zero,” Prasad said.

“Our guide goes deeper than just operational offsetting. It illustrates a ‘whole of life’ approach to buildings — considering where building material comes from, how they are transported to the construction site and so on.”

The best way to minimise the embodied carbon footprint is by retrofitting and reducing materials in use. If that’s not possible, then employing low-carbon materials such as green steel and concrete alternatives during the construction process is best, which is what the guide provides a roadmap for.

The guide also details post-life opportunities for buildings destined to be demolished — creating opportunities to expand the circular economy.

“Buildings don’t have a cradle to grave life cycle,” Prasad said. “It’s more like cradle to cradle. Materials from demolished buildings can go on to have a future life through recycling and reuse.

“For example, it’s possible to avoid demolishing old or undesirable buildings as their concrete structures can stay put and the building can be refurbished.

“Timber, aluminium and glass can be reused or recycled somehow into new products.”

The challenge in the building industry right now is to get past one-off cases and move into a mainstream situation where net zero construction is the norm. Prasad hopes the guide will also help Australia position itself as a leader in the global race to net zero in construction.

The guide is available for download here.

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