Exploring Embodied Carbon Comparison in Lightweight Building Structure Frames: A Case Study

Structural components represent major contributors to embodied carbon emissions of buildings. While there have been numerous research efforts dedicated to modelling and assessing the embodied carbon impact of buildings, there is a conspicuous gap in research that concurrently examines various material options in building structural designs, accounting for technical, economic, and carbon implications. In this study, an integrated approach is applied to assess the embodied carbon and life cycle cost impacts of three different building structures, i.e., timber-framed (TF), steel-framed (SF), and the timber-steel composite (TSCF) framed, scaffolded with Finite Element Analysis (FEA) simulations for a strength and stability analysis of different design options. A lightweight frame-structured residential building type is examined as the data source for the modelling and simulations. The results of a comparative scenario analysis highlight that both TF structures and TSCF structures have notable advantages over their SF counterparts for embodied carbon saving and building load reduction. Assessment results indicate that the TF design offers 35.56% embodied carbon reduction, followed by the TSCF design with 8.12% decarbonization, compared to the SF design. The lifecycle cost assessments also reveal the promising cost saving potential of TF and TSCF structures for the application, with cost savings of up to 7.93% and 4%, respectively. Meanwhile, the simulations further demonstrate that TSCF materials in particular can have significant benefits for lightweight building structures in overcoming the deflection problem of long TF components and the buckling of thin-walled SF members. The results help to identify the potential of TSCF structures to minimize the material use for a "Build with Less" through design optimization, which can lead to further embodied carbon and lifecycle cost reductions.