Construction and demolition (C&D) waste makes up around 70% of material sent to levied landfills in Aotearoa, making it New Zealand’s largest waste stream — but also the one with the biggest potential for reduction.
Recent Ministry for the Environment data shows that soil is the single largest contributor to construction waste, with excavated soils making up the majority of what goes to landfill-type facilities.
“Every truckload of soil sent to landfill represents both a cost and a missed opportunity,” says WasteMINZ chief executive Nic Quilty. “If we plan ahead, design out waste, or reconsider the way that we are treating soil as waste, we can keep thousands of tonnes out of landfill each year.”
WasteMINZ’s Optimising Soil Reuse project is helping to turn that opportunity into reality.
“Soil is the single biggest material we send to landfill, yet it’s also the easiest to rethink. The Optimising Soil Reuse project is about turning what looks like a waste problem into a resource solution, by identifying a vision for soil in New Zealand, finding the gaps in current legislation, and providing recommendations towards a national framework for soil,” Optimising Soil Reuse project chair Rod Lidgard says.
This push comes at a time when the waste and resource recovery sectors are being recognised not only for environmental benefit but for their economic value. A recent report commissioned by WasteMINZ estimates that the waste, resource recovery and contaminated land management sectors contribute over NZD $3.3 billion annually to the national economy, while inefficiencies in disposal are costing the country around $222.8 million in avoidable disposal costs each year. The report also found that an estimated 40% of waste sent to Class 1 landfills is potentially divertible, indicating there’s a huge unrealised opportunity in better material handling and recycling.
This year’s Construction Waste Week – running 27 Oct to 2 Nov and carrying the theme “Plan out the waste. Nail the build” – calls on everyone in the construction sector to make small changes to make a big difference.
Resources and guidance are available via BRANZ, WasteHub, and local council websites to help teams design out waste, recycle and reuse materials, and shift from demolition to deconstruction where possible.
“Designing out waste, deconstructing instead of demolishing, and rethinking soil as a resource - these are the steps that will reduce construction waste to landfill,” Nic says.
Things to note:
- Construction and demolition waste accounts for about 70% of material sent to levied landfills in New Zealand.
- Soil/cleanfill is the largest component by weight in C&D disposal streams.
- The waste, resource recovery and contaminated land sectors contribute over NZD $3.3 billion to New Zealand’s economy, and current waste inefficiencies cost approximately $222.8 million annually.
- The economic report estimates that about 40% of waste to Class 1 landfills is divertible.
- Construction Waste Week 2025 runs from 27 Oct to 2 Nov.
