Worldwide, an estimated 8,300 million metric tonnes of virgin plastics were produced as of 2015. Landfills are the most common method of waste disposal in New Zealand, with almost 50% originating from the C&D (Construction & Demolition) industry in 2006. Construction waste also includes the packaging of building materials to protect them from moisture and damage during transport. Typically, construction activities generate about 1–10% of waste relative to the purchased material. This study, funded by BRANZ, aims to provide data in a format conducive to informing life cycle assessments (LCA) in New Zealand. This information will be utilized by BRANZ to enhance their LCAQuick datasheet containing default waste values for building LCA applications. The methodology employed in this research encompasses a quantitative and descriptive approach, implementing data derived from the material cost estimates of the case study new build and a variety of other primary sources. To achieve conclusive results, primary data sources provided by Nigel Benton, the ESRC (Environmental Solutions Research Centre) research team, and the University of Auckland research team have been utilized to provide a comprehensive and in-depth analysis of case studies. This study found that a total of 7,678 kg of plastic components and materials were procured for the construction of the eight terraced houses. The entire project contained an estimated 6,847 kg of built-in plastics. Lastly, an estimated 11% of the plastic procured became waste during construction, 7% of which can be attributed to packaging, 3% to off-cuts, and 1% to other plastics.