Life cycle assessment of curtain wall facades: A screening study on end-of-life scenarios

By 2030, Australia is committed to reducing 43 % of its greenhouse gas emissions below 2005 record, and achieving net zero emissions by 2050. Embodied carbon emissions in materials used in Australia's building and construction sector are the next frontier to significantly reduce carbon emissions. Facades are among the highest contributors to embodied carbon emissions in commercial buildings. However, there are limited studies on the life cycle assessment examining the embodied impacts of different types of curtain walls. Further, the majority focus on the upfront carbon, oversimplifying the end-of-life (EoL) possibilities, often assuming demolition as the only scenario. This study explores the life cycle assessment of three facade systems from cradle-tograve analysing the trade-off between the impacts of the service life and end-of-life stages to identify the associated environmental benefits. A total of 27 scenarios based on different facade service lives of 20, 40 and 100 years and different EoL scenarios, including landfill, recycling and reuse are examined. The assessed variables include the global warming potential (GWP), total use of renewable primary energy resources (PERT), total use of non-renewable primary energy resources (PENRT) and net freshwater use (FW). This study highlighted the importance of considering the net benefits beyond the boundary. Compared to recycling, reuse provides more net benefits to GWP, PERT and PENRT. By extending the facade lifespan, the uncertainty of the impact indicators associated with different EoL decreases. Moreover, the life cycle benefits of selecting a facade with higher operational savings increases, given the same EoL scenario.