As a parent, Green Star Auditor and a member of the group working on improving the NZGBC Green Star Buildings NZ Construction & Demolition Waste Reporting Criteria, I have a natural interest in what is happening in the building waste area. So when I received the report: Australia’s waste(d) opportunity 2025 by Coreo, I had to have a closer look. It was an interesting read!
The report highlights the staggering amount of waste generated by the construction sector:
- 29 million tonnes annually and the economic impact of wasted materials, which could cost up to $64 billion over the next five years, with an average of $384 wasted per square meter in new building construction
Of other key findings is that:
- new building construction projects waste an average of 141 kg/m², while
- fitout projects waste 37.3 kg/m².
According to the report, Australia is only 4.6% circular, meaning 95.4% of consumed resources are virgin materials. Increasing circularity can therefore save billions and reduce environmental impact.
The report also found that the top wasted materials were mixed concrete, masonry, tiles, soil, sand, rubble fines, and timber. Interestingly, high diversion rates (90%) are reported, but actual recycling rates are much lower due to material losses during collection and processing.
There is no doubt we still have a long way to go, also here in New Zealand. In relation to this, the report also had a list of recommendations:
Design for Circularity:
- Use modular, adaptable designs to reduce waste.
- Prioritize reuse of existing structures over demolition.
- Develop disassembly plans for future reuse of materials.
Improve Reporting:
- Standardise waste reporting templates to track material flows accurately.
- Focus on actual recycling outcomes rather than diversion rates.
Policy Changes:
- Embed circular economy targets in national, state, and local policies.
- Offer financial incentives for projects achieving high material recovery and reuse.
Industry Collaboration:
- Engage stakeholders across the value chain (architects, contractors, waste managers) to reduce waste and improve material management.
There is definitely a lot we can do, and, according to the report, there are a few success stories, showing that we can do better. For example Brisbane Midtown Centre: Adaptive reuse of two office towers saved 11,000 tonnes of carbon and reduced construction costs by 25% and Curtin University Legacy Living Lab: Designed for disassembly, 78% of materials can be reused at least three times, reducing demolition emissions by 90%.
Being an auditor in the waste industry, I will line out a few learnings from the report to the industry:
- Focus on High-Impact Projects. Waste companies should prioritize
- New Building Construction: Mixed-use and commercial developments generate significant waste, offering opportunities for material recovery and recycling
- Fitout Construction: Frequent refurbishment cycles (every 5-7 years) in commercial and retail fitouts create a goldmine for reuse and recycling.
- Embrace Circular Economy Practices
- Collaborate with developers to implement modular design, disassembly planning, and material reuse pathways.
- Focus on high-impact materials like mixed concrete, masonry, tiles, timber, and lighting/e-waste.
- Support Green Star Projects
- Assist projects pursuing Green Star ratings, which require high landfill diversion rates and material recovery efforts.
- Prepare for more detailed Green Star reporting requirements.
- Improve Reporting and Tracking
- Develop systems to track materials post-collection, ensuring they are recycled or reused rather than downcycled or sent to landfill.
- Provide accurate data on material recovery rates to improve transparency and accountability.
- Expand Decommissioning Services
- Work on demolition and deconstruction projects to recover reusable materials.
- Facilitate the listing of reusable materials on marketplaces to reduce reliance on virgin resources.
- Invest in Material Recovery Facilities
- Establish or enhance facilities to improve sorting, tracking, and recycling processes.
- Focus on materials with high recovery potential, such as timber, metals, and plasterboard.
The bottomline of this report is that the construction industry’s waste problem is not just an environmental issue - it’s an economic opportunity. Each percentage point improvement in circularity represents billions in potential productivity.
Waste companies are uniquely positioned to lead the charge in reducing landfill contributions, increasing material recovery, and supporting the industry’s transition to sustainable practices. It has therefore been great to see New Zealand waste companies, being active in improving the Green Star Reporting Criteria, and some of them, investing in sorting sites, not only to divert, but also to recycle and reuse and to become part of building a more circular and thereby sustainable economy in New Zealand.
