Minimising upfront carbon emissions of steel-framed modular housing: A case study

• Published in: Journal of Building Engineering 2023-08, Vol.72, p.106707, Article 106707
• Main Authors: Kechidi, Smail, Banks, Nigel
• Format: Article
• Language: English
• Subjects: Climate change; Embodied carbon; Lifecycle assessment; Modern methods of construction; Upfront carbon
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2023.106707

In this paper, a roadmap for reducing upfront carbon emissions of steel-framed modular housing has been laid out. In order to generate the required data for the appraisal of the roadmap, embodied carbon assessments have been carried out on two versions of a 2-bedroom 4-person 81 m2 modular house. A standard version is adopted as a benchmark house and an upgraded version entitled “Refresh” in which improvements in material design efficiency have been made. The Refresh design has 12% lower upfront carbon emissions as this has been designed to minimise materials, and when extrapolated across 2000 homes per year produced, it results in 6000 tCO2e upfront emissions saving. Further material design efficiency and specifying low carbon materials were explored which led to a further 43% lower upfront carbon emissions. Subsequently, supply chain and replacement materials decarbonisation projections, as well as improvements in the transportation of materials and construction site practices, have been modelled to forecast the upfront emissions up to 2050. The results shed light on the importance of removing the reliance on materials that have a large amount of carbon capture and storage in their decarbonisation strategies and reducing upfront carbon emissions today rather than waiting for the materials industries to act in the future. The above-described outcomes have equipped ilke Homes with a commercially viable and scalable solution with low upfront carbon emissions to deliver net-zero carbon houses while helping to achieve the UK Government's housing targets (i.e. 300 000 new homes per year by mid-2020s). •A roadmap for reducing upfront carbon emissions of steel-framed modular housing.•Establishing steps to design with the minimum amount of materials.•Minimising the carbon footprint with a strategic supply of materials.•Modelling of supply chain and replacement materials decarbonisation projections.•Modelling of improvements in transportation and construction site practices.