Whole life cycle carbon in Construction: A systematic review of Policy, planning and assessment tools (2012–2024)

• Systematic review of 52 studies on whole-life carbon in construction (2012–2024). • Identifies structural gaps in carbon governance, early-stage integration, and material waste modelling. • Reveals fragmented carbon policies and uneven global access to LCA datasets. • Highlights methodological limitations of current LCA tools, including reliance on proxy data and limited interoperability. • Advocates integrated carbon governance and early-stage carbon-informed decision-making to strengthen implementation. The construction sector accounts for approximately 37% of global energy and process-related CO 2 emissions, making it a critical domain for decarbonisation efforts. While operational carbon from building energy use has long been addressed through regulatory and technological strategies, embodied carbon remains underexplored in both policy and practice. Embodied carbon includes emissions from material extraction, production, transportation, construction activities, and end-of-life processes. Reducing these emissions requires early-stage intervention, robust policy frameworks and integrated tools for assessment and decision-making. This study conducts a systematic literature review of peer-reviewed research published between 2012 and 2024, using the PRISMA methodology to ensure transparency and replicability through a multi-dimensional comparative coding framework that enabled systematic cross-study comparison and thematic consolidation to examine how embodied and operational carbon have been incorporated into (1) legislative frameworks, (2) early-stage planning and design, and (3) material- and waste-related mitigation strategies. Findings reveal growing attention to whole-life carbon, alongside notable progress in software development and voluntary standards. However, three persistent gaps are identified: (a) weak enforcement and limited standardisation in policy; (b) insufficient integration of carbon metrics during early design; and (c) systematic exclusion of material waste and circular strategies in contemporary life cycle assessment (LCA) practice. In addition, the review identifies structural barriers, including reliance on proxy datasets and late-stage carbon evaluation, which limit practical implementation despite methodological advances. This review synthesises fragmented knowledge across policy, planning, and materials, offering practical recommendations for policymakers, practitioners, and software developers. Although the reviewed corpus is predominantly European in orientation, the identified patterns reveal broader systemic dynamics relevant to global construction contexts. It also outlines future research priorities, including interoperability of digital tools, carbon benchmarking, and regional adaptation. Achieving net-zero targets in construction will require not only better tools and data but also institutional reform and cultural change across the sector.