Life-cycle assessment (LCA) studies are the main tool used to measure the carbon footprints of building products at each phase of their cradle-to-grave lifespan (i.e. production, use, and end of life). While LCAs are the best-available tool for evaluating the greenhouse gas (GHG) performance of alternative building products and designs, policy makers and building designers should be aware there are also limitations, challenges, and uncertainties. Therefore, the purpose of this report is to identify:
- Limitations, challenges, and uncertainties in existing LCAs and quantify their significance to the current understanding of the relative GHG performance of buildings made alternatively of concrete, steel, or wood structural elements.
- Best practices that could improve the reliability and usefulness of LCA to support effective policies to decarbonise the built environment.
- Longer-term opportunities to reduce life-cycle emissions in the built environment by supporting decarbonisation efforts in the concrete, steel, and forestry sectors.
The report includes three key recommendations:
- Building efficiency and longevity should be the priority for decarbonising the built environment.
- LCA is the right approach, but more data, transparency, and robust standards are needed, especially with respect to biogenic carbon.
- To address embodied GHG emissions in buildings, policy makers and building professionals need to focus equally on material efficiency and incenting decarbonisation across all material manufacturing sectors.