Comparison of GHG emissions from circular and conventional building components

• Main Authors: Camilla Ernst Andersen, Kai Kanafani, Regitze Kjær Zimmermann, Freja Nygaard Rasmussen, Harpa Birgisdóttir
• Format: Article
• Language: English
• Published: Ubiquity Press 2020-07-01
• Series: Buildings & Cities
• Subjects: buildings; carbon metrics; circular economy; components; embodied carbon; life-cycle assessment; reuse
• Online Access: https://journal-buildingscities.org/articles/55

The concept of circular economy has been introduced as a strategy to reduce the greenhouse gas (GHG) emissions from buildings and mitigate climate change. Although many innovative circular solutions exist, the business model is challenged by a lack of environmental data on the circular solutions, and thus the potential benefits are not verifiable. The study assesses the embodied GHG emissions of five circular building elements/components. Circular solutions are compared with conventional solutions to ascertain whether the business model has the potential to reduce GHG emissions. The GHG emissions are quantified using life-cycle assessment (LCA) for five circular-economy and three conventional building elements/components. The environmental data show that circular building components have the potential to reduce GHG emissions. However, there is a risk of increasing the GHG emissions when compared with conventional solutions, emphasising the need for standardised environmental data. Lastly, the study identifies logistic, economic, technological and regulatory barriers that prevent complete implementation of circular economy.   'Practice relevance' Standardised environmental data on building elements/components are needed to support decision-making at local and national levels. Uncertainties about waste from manufacture and transport in the production stage can affect the environmental potential to such an extent that the benefits from introducing circular economy are lost. One central barrier is identified that prevents complete implementation of the circular economy in buildings; the industry is not geared to support a steady supply of some circular building elements/components. In general, it is clear that the implementation of circular economy requires the identification of environmental, logistical, economic, technological and regulatory concerns.