Landfill Waste Diversion in Residential Projects in New Zealand

In recent years, the zero-waste objective has garnered significant attention from researchers and policymakers as a promising approach to mitigate the environmental impacts of the construction industry, with the goal of diverting 100% of waste from landfills and maximising resource recovery. In New Zealand (NZ), while various policies and initiatives have been implemented across the country, limited empirical studies have investigated the status of waste diversion in construction projects. To address this research gap, the authors analysed 160 residential projects across six cities in NZ, using waste reports and site waste management plans (SWMPs) to evaluate current waste diversion practices. Quantitative data in the waste report was used to calculate the landfill waste rate (LWR), waste generation rate (WGR), and waste diversion rate (WDR) for descriptive analysis. These results were further investigated through an analysis of SWMPs. The findings reveal regional differences in the amount of construction waste (CW) sent to landfills, influenced by on-site sorting practices and the availability of local off-site sorting and recycling infrastructure. These insights are crucial for waste managers and policymakers in developing strategies and regulations to minimise waste in the construction sector.