ABSTRACT Construction and Demolition (C&D) waste is an environmental, economic, and resource‐efficiency challenge in New Zealand (NZ), yet detailed stage‐specific quantification of residential construction waste remains limited. This study presents a validated case study of waste generation from three residential units, introducing a multi‐method approach that combines on‐site visual observation of filled bins, photographic image analysis, document analysis, professional assessment, and verification against resource recovery centre measurements. A total of 8.4 t of waste was generated during the monitored construction stages (22.7 kg/m 2 ), increasing to 29.4 kg/m 2 when external works such as fencing and landscaping were included. Waste generation intensity and stage‐normalised waste rates (kg/m 2 and kg/day) were calculated to enable benchmarking with international studies. Internal wall linings produced the largest proportion of waste (34%), followed by cavity and cladding (21%) and wall framing (11%). Waste streams such as timber (44%), plasterboard (28%), and metals (15%) together accounted for 86% of total waste. Robust statistical measures, including deviation, were applied to evaluate variability and identify high‐waste construction stages. Validation exercises demonstrated that experienced industry professionals estimate major waste streams with a deviation of 6.5%, while image‐based estimates showed only 1% –6% variation from Resource Recovery Centre (RRC) measurements. Analysis indicates that up to 93% of waste could potentially be diverted from landfill using existing recycling pathways through stage‐aligned onsite sorting practices. This study offers preliminary insights to analyse waste performance and supporting circular economy strategies in the construction sector.
Gade et al. (Sun,) studied this question.