In the quest to build greener, more efficient structures, the construction industry has long looked to modern methods of construction (MMC) as a potential panacea. These methods, which include prefabrication, off-site construction, and industrialised construction, promise to revolutionise how we build, but do they live up to their environmental hype? A groundbreaking study led by Richard O’Hegarty of the School of Architecture, Planning and Environmental Policy at University College Dublin, has delved into the embodied carbon credentials of MMC, and the findings are as surprising as they are enlightening.
The study, published in Buildings & Cities, critically reviewed 250 separate studies and distilled them to a final sample set of 41 studies and a total of 82 case study comparisons. The goal was to assess whether MMC truly delivers on its promise of reducing embodied carbon—the total greenhouse gas emissions associated with the production, transportation, and assembly of building materials.
O’Hegarty’s findings challenge the prevailing narrative. “There is a general perception that the adoption of MMC results in embodied carbon savings,” he notes, “but the evidence to support this claim is not robust.” The study reveals that the impact of MMC on embodied carbon is far from straightforward. Individual case studies showed significant variability, with some indicating savings and others showing increases in carbon emissions. This variability underscores the complexity of embodied carbon assessments and the need for a more nuanced approach.
The implications for the energy sector are profound. As the construction industry grapples with the urgent need to reduce carbon emissions, the assumption that MMC will automatically lead to lower embodied carbon is being called into question. This research suggests that reducing the embodied carbon of buildings requires a case-by-case assessment, rather than a one-size-fits-all solution.
For energy sector professionals, this means a shift in strategy. Rather than relying on MMC as a silver bullet, the focus should be on comprehensive life cycle analyses and tailored solutions. This could involve innovative materials, optimised supply chains, and advanced manufacturing techniques that specifically target carbon reduction.
The study also highlights the importance of policy relevance. MMC has been widely promoted as a solution to housing shortages and productivity issues, but the environmental benefits are less clear. Policymakers and industry leaders must now consider the embodied carbon implications more carefully, ensuring that any push for MMC is backed by robust data and tailored strategies.
As the construction industry continues to evolve, this research serves as a wake-up call. It challenges us to think more critically about the environmental impacts of our building methods and to seek out solutions that are truly sustainable. The journey towards net-zero emissions in the built environment is complex, but with a more nuanced understanding of embodied carbon, the industry can make more informed decisions.
The study by O’Hegarty and his team, published in Buildings & Cities, is a significant step forward in this journey. It provides a critical review of the embodied carbon credentials of MMC, offering valuable insights for industry professionals, policymakers, and researchers alike. As we move forward, the focus must be on data-driven decisions and tailored solutions that truly deliver on the promise of a greener, more sustainable future.
