Practices for Reducing Embodied Carbon (EC) Emissions in New Zealand Commercial Construction

This study explores the practices used to calculate and reduce embodied carbon (EC) on New Zealand (NZ)) commercial construction projects. EC represents the carbon dioxide emitted into the atmosphere throughout the extraction, fabrication, transporting, and assembling of building materials. NZ has set a target under the Paris Agreement to reduce net greenhouse gas emissions to 50 per cent below gross 2005 levels by 2030. Construction is a substantial contributor of EC. A survey questionnaire was distributed to construction stakeholders. The survey tested and expanded on tested previous interview findings. The questionnaire was posted on the New Zealand Institute of Quantity Surveying (NZIQS) forum and received 41 responses. From these responses, 19 had not been sufficiently completed, and therefore, the results of the remaining 22 were adapted and used in the data analysis. Calculating and reducing EC is not mandatory in NZ. However, the findings show that most industry professionals are yet to experience EC calculation on projects. Clients most commonly drive EC reduction and on public projects with calculations conducted often during concept or detailed design stages. The challenges with measuring and lowering EC include a lack of client willingness to fund EC calculation, lack of knowledge and experience, lack of previous cost data, lack of low-carbon materials, and no fit for purpose EC calculation tool. The findings support previous literature that a fit for purpose calculation tool is required, ideally suitable for a whole project lifecycle. Findings may inform NZ government policy initiatives towards supporting EC reduction towards meeting their 2050 target.