The construction industry called to reduce carbon emissions

Advocates of sustainable construction want the construction sector to receive a clear signal to reduce its carbon emissions.

Statistics New Zealand said that emissions from the construction sector had jumped 66% over the decade until 2017.

The sector is already trying to adapt, but some have said that it would need help to justify the investment.

The creation of cement is inherently intensive in carbon, with a chemical reaction that decarbonizes the limestone.

Fletcher Building operates the country's largest cement manufacturer, Golden Bay Cement, which generates 700,000 tonnes of carbon in one year.

"Nearly 70% of the carbon emitted comes from the process of converting limestone into cement cement or clinker," said Concrete Division General Manager Ian Jones.

"So we can work hard on the remaining 30%, which comes from energy, usually coal, but we also need to figure out how to actually reduce the amount of cement we use."

Golden Bay Cement reduced its energy emissions by 50,000 tons by replacing some of its coal fuel with wood chips in 2004, and is currently using old tires as an alternative.

"The main challenges are the need to make technical changes to a product that the market has been using for years," Ian Jones said.

The search for cement alternatives that could provide the same properties of concrete is already underway.

"If we could mix 20% of alternative materials with a carbon footprint zero or close to it, we could reduce emissions by 20% in New Zealand." This investment right, and we have to make sure that the market will actually take this alternative product.

"People like and want better environmental qualities, but in reality, paying more for it is probably not there yet, but it will evolve over time."

Last year, a report estimated that buildings contribute 20% of the country's carbon footprint throughout their life cycle.

The author of this report and technical director of the consulting company, Thinkstep Australasia Jeff Vickers, said that it was difficult to change a lot of key materials like cement and steel.

"Regarding this side, manufacturers need to be certain that by changing a process, people will be willing to pay for these improved, low-carbon materials."

But, as people were already complaining about high construction costs, he said that it would require collaboration between manufacturers, consumers and the government to help the industry justify its investments.

"This could be for example that the government says" for all public buildings, whether it's schools or hospitals or whatever we do, we're going to say that we will buy materials with this set of criteria. "Then, through their important role as a supplier of materials and building products, they could then help lead the change," said Jeff Vickers.

The government's framework for achieving its climate change goals is through parliament.

Public submissions on the government's Zero Carbon Bill were wrapped up earlier this week, and the Green Building Council said it was an opportunity for the industry.

"What we really need is to get out of this to have a really clear mandate: to target buildings and homes as well," said Andrew Eagles, CEO.

Under the act, the government would create an independent climate change commission to advise and empower them.

"We ask one of the commissioners to have experience and know-how in the built environment in this area."

Andrew Eagles said the industry would be receptive if clear goals were set and the government had to commit to meeting sustainable standards.

"The second thing the government could do is to begin to include elements such as embodied carbon and energy efficiency in the building code for future regulation.This is a pipeline driving change."