The construction industry chase for zero waste

Saturday, 8 June 2024

Too much of landfill waste comes from construction, so Greg Parsonson challenged his company to divert 95% of the waste from its next project away from landfills.

Parsonson, who is a director of commercial fit out company Cachet Group, knew the goal was an ambitious one, so he did not expect it to be bettered.

But it was, with 99%, or 20.8m³ of the construction waste from its recent fit out of a retail bank in Auckland’s St Lukes Mall not going to landfill.

That success has inspired him to spread the word about what could be done by the rest of the industry.

Construction waste is estimated to make up 40% to 50% of the waste that goes into landfills.

As recently as 2021, construction and demolition in Auckland alone produced nearly 570,000 tonnes of waste a year, roughly half the entire landfill volume and equivalent to 23,155 shipping containers of rubbish.

Parsonson said given those figures the sector’s opportunity to materially impact on the country’s sustainability efforts was huge.

His company had incorporated ESG principles into fitouts before, but after going to a Green Building Council event last year he was inspired to do something more.

“Part of the nature of what we do, fitouts, is that they can be wasteful in nature as they revolve around putting things in and taking them out, especially in retail fit outs,” he said.

“I started thinking about not just what is recyclable after a project is completed, but what happens on a build itself. With our client, we decided to set a specific waste minimisation goal on this project.

They wanted to push boundaries, but found it was not easy because industry norms supporting green construction were not well-established yet, he said.

“There is no accreditation programme in this space, and no pathway to follow for waste management in fitouts, so there’s a bit of a gap in the market.”

But they focused on identifying and verifying contractors and materials, strict specifications during design and procurement, and later managing the site in a way that supported their waste elimination goals.

“We worked with the supply chain on procurement to select the best materials to use, and also to clarify how we wanted them packaged, delivered, and installed to minimise waste,” he said.

“A lot of waste is from the packaging: plaster board usually arrives wrapped in plastic for example. So we requested that our stock not be wrapped in plastic.”

The company also looked at every product used, down to tubes of glue, identified if it could be recycled and how, and focused on a bin disposal system to ensure products went where they were supposed to.

Once the project was underway, there was continuous monitoring of waste practices by site management.

That included monitoring even the smallest of details, such as ensuring contractors had reusable rather than disposable coffee cups, and banning single use and non-recyclable food packaging on site.

Sustainable waste management company Junk Run was commissioned to remove and divert recyclable waste from the site, and report on the results of the waste diversion efforts.

Parsonson said while they were close to achieving true zero waste on the project, they found no commercially viable way to rehome a small percentage of waste from the site.

The non-recyclable material included dust, cable ties and smaller hard plastics, such as lids from glue.

“We even looked at creative solutions for diverting the dust, such as commissioning a local artist to craft with it, but this wasn’t practical.”

Achieving 99% waste diversion was a lot of work, but it showed how much the industry could do to reduce waste, he said.

“There are no waste reduction schemes on most sites. Just go past a skip on most sites, and see how much is in it.

“But doing more is relatively simple. Companies need to change the way they think about the products they use, and what they throw in skips, even down to the little things.

“It’s not just about recycling, it is about minimising waste in the first place.”

Parsonson hoped that as projects like Cachet’s one became more common, waste management practices would improve, and support an industry-wide shift towards their adoption.

“We are taking the learnings we’ve gained, and doing it all again with a new office fit-out for MYOB in an Auckland-based six green star building.

“But it’s fantastic to see demand and expertise growing across the sector with more project partners keen to be part of the journey.”

Cachet worked with the Environmental Innovation Centre on the project, and the centre’s co-director Dr Terri-Ann Berry applauded what the company had done.

“By being ambitious, they are demonstrating to other companies and sectors what is possible in a practical, accessible way,” she said.

“It is key to bring more people along on the journey, and to show them tangible solutions that actually help to reduce waste.”

But it was unfortunate that New Zealand did not have the infrastructure to achieve zero waste on construction sites yet, she said.

“Some materials just don't have a suitable recycling option available while others, although theoretically recyclable, are very difficult to separate in a way that is clean enough for recycling.”

Commercial drivers, such as the cost of labour in construction, meant waste management needed to be practical and efficient to be viable, she said.

“Some companies might think they are too small to make a difference, but when lots of companies come together, especially across sectors, and adopt better practices, it does make a difference.”