Here’s what construction is doing about its waste problem
Tuesday, 23 September 2025
A host of homegrown solutions are tackling the construction industry’s enduring waste problem, even though the downturn means there is currently less of it.
Recent data from the Waste & Recycling Industry Forum showed the amount of waste generated nationwide dropped sharply to 3.7 million tonnes last year, driven mainly by a 23% fall in waste from commercial and industrial sites.
But the forum’s executive director, Barney Irvine, said it reflected the depressed state of the construction sector, which made up the bulk of the waste sent to landfill.
The public and policy-makers should be under no illusions about the fact the amount would rise again as soon as the economy started to recover, he said.
Construction waste is estimated to make up 40% to 50% of the waste that goes into the country’s landfills, and the typical new home build produces about four tonnes of waste.
The industry is aware the problem is not going away, and a range of groups have introduced initiatives to address it. Here’s a selection of them.
Mitre-10 has collaborated with 3R Group to develop an industry-led initiative that helps residential builders to reduce waste and adopt more sustainable practices that can be easily implemented on sites.
The initiative, Sustainability On-Site, is an online portal featuring builder-hosted videos on topics such as creating waste minimisation plans and how to sort waste. PDFs of similar content will be added in future.
Content also highlights how sustainable practices could save businesses money by improving efficiency and reducing waste-related costs.
Mitre 10 head of sustainability, Julie Roberts, said most tradies wanted to do the right thing but they needed practical guidance and the tools to do it.
“We saw an opportunity to work with partners, such as BRANZ, to take the academic work and information in this space, and make it really user friendly for trade customers.
“Builders don’t need more complexity – they need solutions that work in the real world. The portal makes it easy for them to do the right thing, and is grounded in the day-to-day realities of the job site.”
The industry had taken to the initiative well, and the take up in associated waste diversion and recycling programmes had been strong, she said.
Some examples were the diversion of 52,000 cubic metres of Expol polystyrene through Mitre 10 stores since 2022, and the diversion of over 40 tonnes of paint since October last year. The polystyrene was recycled, and the paint was made into a new product, RePaint, sold in Mitre 10 stores.
“People are motivated to make small changes that add up, and the trade sector has a big group of practical people that want to make things happen.”
A “truly circular” system
Shrinkwrap is one of the more visible waste products on building sites. That visibility made it look bad, although it did not actually make up a huge amount of waste, Environmental Innovation Centre co-director Terri-Ann Berry said.
But the shrinkwrap sector industry recognised it had a part to play in reducing construction waste, and set out to find a solution.
The end result was Shrinkwrap Supplies’ business, Goodwrap Recycling, which was supported by the centre and the New Zealand Association for Scaffolding, Access and Rigging (SARNZ).
Berry said the programme, which was voluntary, made it easy for users of shrinkwrap to not only recycle it but to contribute to another product.
Users receive free recycling bags with their wrap orders, wrap is put in the bags as it is removed, and full bags are taken to Mainfreight depots to be sent to Auckland for grading and processing into new resin for use in local manufacturing.
“Shrinkwrap is a good quality product that should be recycled and kept in a closed-loop, and this programme does that,” she said.
“It is a truly circular scheme, which ensures the product goes round and is reused for potentially a very long time, rather than going to landfill.”
The programme helped reduce the carbon footprint by reprocessing the product locally, and eliminates landfill costs associated with disposing of used wrap, she said.
SARNZ chief executive Tina Wieczorek said the programme was believed to be a world-first, and did not cost a fortune.
“Transportation utilises reverse logistics with Mainfreight, so there are no added emissions or costs, and there’s a full tracking system so businesses can be assured it’s not ending up in an overseas landfill.’
The uptake had been swift with many tier one companies now including it in their procurement needs, she said.
Innovative developments
New Zealand’s concrete industry is committed to decarbonisation, and Concrete NZ’s latest sustainability report examined its shift to more efficiency in concrete production and delivery.
Tim Kleier, sustainability and policy director Concrete NZ, said that was a critical lever in reducing the industry’s footprint.
To that end, waste wood and tyres were increasingly used to replace coal as material in production, while waste glass, chipped tyres, and aggregates could be used in ready mixed concrete and masonry.
Those developments contributed meaningfully to waste reduction and resource recovery, the report said.
One of its featured case studies was Kayasand Engineered Sand, an initiative that transformed quarry by-product into high-performance engineered sand, reducing reliance on natural sand.
Kleire said local companies were embracing technology and innovation to reduce emissions, strengthen resilience, and support the shift towards a circular economy.
On the building materials front, another recent waste reduction initiative is a Hawkes Bay plasterboard recycling trial.
A collaboration between Hastings District and Napier City councils, Winstone Wallboards and local building supplies merchants, it has seen nearly 14 tonnes of GIB diverted from Hawkes Bay landfills since May this year.
And SaveBoard, the Kiwi company that pioneered multi-use building panels using recycled packaging waste, recently announced it had formed a new partnership to create a flooring product made from recycled soft plastics and used carpet.
The goal was to capture and use some of the 90,000 tonnes in used carpet from residential and commercial builds heading to landfill each year.
SaveBoard founder and chief executive Paul Charteris said that internationally there was limited carpet recycling, and turning waste carpet into a flooring product was a world-first.
It was about giving waste a second life and giving the industry a new path forward, he said.