Topology Optimization Approach to Reducing Carbon Emissions in Landscape Structures

Landscape structures generate significant life-cycle embodied carbon due to material redundancy and low structural efficiency. While topology optimization provides a scientific basis for material reduction, its resulting free-form surfaces and complex joints often hinder manufacturing and on-site assembly. This study introduces the Design for Manufacture and Assembly (DfMA) method to address these challenges, using landscape benches, pavilions, and bridges in the Beijing Olympic Forest Park as case studies. After data collection, we performed topology optimization via Autodesk Fusion and applied DfMA principles to simplify complex topological forms into standardized, modular structural systems. Life-cycle embodied carbon emissions were then compared across initial, topology-optimized, and DfMA-simplified designs. The results indicate that while topology optimization reduces material usage by 19–85%, it may increase total carbon emissions, especially in complex metal structures, due to higher construction energy demands and recycling difficulties. In contrast, DfMA simplification significantly improves manufacturing feasibility, cutting total carbon emissions by 33–64% compared to initial designs. The material production phase exhibited the most prominent carbon reduction, contributing an average of 60% to total emission savings. Ultimately, this study highlights that topology optimization alone is not universally carbon-reducing, and it requires DfMA-oriented simplification to achieve reliable low-carbon outcomes.