ER108 Plastic waste in construction Report 1 - Auditing 6 sites in Auckland (2025)

Despite the significant contribution to plastic waste made from the C&D sector, there is a general lack of knowledge and focus on plastic waste management from C&D activities. This research investigated the plastic waste produced by a variety of construction sites in Auckland and explored options for landfill diversion.

Six Auckland construction sites were selected for plastic waste auditing. A total of 7.2 tonnes of plastic waste was audited across the six Auckland sites and categorised into 46 groups (see Appendix for full data). A range of different plastic products were used over the sites, including shrink wrap, woven plastics, vinyl flooring and adhesive weather barrier. It was observed that the sites generated the highest quantities of plastic waste during the final stages of construction. Plastic waste largely originated from packaging (e.g. soft plastics and polystyrene), followed by construction components (e.g. plastic pipes, damp-proof membrane (DPM), vinyl flooring) and building protection (e.g. shrink wrap, woven plastics).

Problematic plastic waste types that cannot be processed easily by recycling operators and/or were generated in relatively large amounts included backing films from adhesive weather barriers, woven plastics, cross-linked PEX pipes and composite cable reels. Another problematic waste type was fibre-cement cladding, which could not be recycled at the time of this study. This report discusses the plastic waste data from the research.