Circular economy approaches for improving environmental and economic performance of felt-based living walls.

This study investigates whether an optimised living wall (LW) system can outperform current business-as-usual (BAU) practices in Australia in terms of environmental and economic performance. A comparative life cycle assessment (LCA) and life cycle cost analysis (LCCA) were conducted over a 30-year service life to evaluate an optimised LW system against a BAU scenario. Compared with the BAU-LW, the OPT-LW system achieved a 68% reduction in global warming potential, a 49% decrease in ozone depletion potential, and a 64% reduction in fossil resource depletion. Lifecycle cost decreased by 48%, indicating strong alignment between environmental and financial performance. Sensitivity analysis showed that environmental outcomes were highly sensitive to the electricity profile and service life, while cost factors remained largely insensitive to user engagement, hourly rate, and inflation. Overall, the OPT-LW system offers a feasible pathway toward lowcarbon, cost-efficient vertical greening with robust long-term sustainability. Despite these gains, LCA/LCCA do not capture broader benefits such as biodiversity, mental well-being, and urban heat mitigation. This study demonstrates that optimised felt-based living walls can substantially reduce environmental impacts and lifecycle costs, highlighting their potential as a more sustainable and cost-effective solution for buildings. However, the broader adoption of such systems is limited by current property development practices, suggesting that policy interventions and financial incentives are needed to enable wider implementation.