Unveiling the Embodied Carbon of Construction Materials through a Product-Based Carbon Labeling Scheme

Abstract

In order to mitigate the adverse impacts caused by climate change, governments around the world have set ambitious targets to reduce the carbon intensity of their country. Achieving those emission reduction targets necessitates the active participation of the construction industry as the manufacturing of construction materials could contribute to 70 percent of greenhouse gases (GHG) emissions at the construction stage or 15 percent of a building’s life time energy consumption. Minimizing the GHGs generated from the construction industry through prudent selection of “low carbon” construction materials is, therefore, imperative. This paper reports a study initiated by the Construction Industry Council, Hong Kong which aims to establish a holistic framework for assessing the life cycle carbon footprint of construction materials at the product level. By benchmarking the emission level of a specific construction material against the norm, a carbon label can be awarded to delineate a low carbon construction material from the others. The carbon labelling framework of construction materials described in this paper is one of the pioneering product-based life cycle carbon footprint assessment tools for the construction industry. The proposed carbon labelling scheme not only allows suppliers and/or manufacturers of construction materials to communicate to their consumers in terms of the carbon footprint of their products amongst other products within the same product category, it would also help realize continuous product and design improvement and thus help reduce the carbon footprint of construction facilities relentlessly. More importantly, developers, designers, and contractors can procure certified low carbon construction products so as to facilitate the construction of greener and lower carbon facilities. In this paper, the features of the carbon labelling scheme for construction materials including the scope of the scheme, the material classification regime as well as the assessment and benchmarking mechanisms will first be introduced. The paper will then highlight the strategies to introduce the carbon labelling scheme to construction projects. Finally, the future development of the carbon labelling scheme will be discussed.