Embodied Carbon in New Zealand Commercial Construction

Abstract

Decarbonization is gaining priority from the macro to the micro level. However, achieving this is a critical challenge, as industries are still immature. This study explores the practices used to calculate and reduce embodied carbon (EC) in New Zealand (NZ) commercial construction projects. In the Paris Agreement, NZ pledged to reduce its net GHG emissions to 50 percent below the gross 2005 levels by 2030. The built environment generates approximately 40% of global greenhouse gas (GHG) emissions, with 11% being generated by manufacturing materials. EC represents carbon dioxide (CO2) emitted into the atmosphere throughout the extraction, fabrication, transportation, and assembly of building materials. A survey questionnaire was distributed to stakeholders in commercial construction via the New Zealand Institute of Quantity Surveyors (NZIQS) open forum. Twenty-seven valid responses were analyzed. The survey tested and expanded on the interview findings. Calculating and reducing EC are not mandatory in NZ. Most industry professionals had yet to experience EC calculation in projects. Clients most commonly drive EC reduction in public projects with calculations that are often conducted during the concept or detailed design stages. The challenges in 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 EC materials, and lack of fit-for-purpose EC calculation tools. These findings may inform NZ government policy initiatives supporting EC reduction to meet their 2050 target.