Abstract

Public infrastructure projects are significant contributors to global carbon emissions, largely due to energy-intensive construction processes, material production, and complex supply chains. The growing urgency to mitigate climate change has highlighted the need for low-carbon procurement and contracting systems that embed sustainability principles into public infrastructure delivery. Such systems prioritize emission reduction across the project lifecycle, from design and material sourcing to construction, operation, and maintenance, aligning economic, environmental, and social objectives. This presents a conceptual model for low-carbon procurement and contracting, integrating governance, technical, operational, and evaluative components to guide sustainable public infrastructure delivery. The model emphasizes policy and regulatory alignment, including carbon reduction targets, green procurement guidelines, and emission reporting standards, to create an enabling environment for low-carbon adoption. It incorporates procurement strategies such as lifecycle carbon assessment, supplier evaluation, and low-carbon specification standards, alongside contracting mechanisms including performance-based contracts, emission accountability clauses, and incentive structures for sustainable practices. Operationally, the framework addresses sustainable materials sourcing, logistics optimization, and integration of digital tools for real-time carbon tracking and monitoring. Continuous evaluation and learning processes are included to measure performance, facilitate iterative improvements, and ensure long-term resilience and sustainability. Key insights reveal the potential of the conceptual model to reduce lifecycle carbon emissions, enhance resource efficiency, and improve environmental and social outcomes in public infrastructure delivery. The framework also highlights the importance of multi-stakeholder collaboration, involving policymakers, procurement authorities, contractors, and communities, to ensure contextually appropriate and effective implementation. By providing a structured approach for embedding low-carbon principles into procurement and contracting, this model offers actionable guidance for both practice and policy. It serves as a foundation for future empirical studies, pilot projects, and capacity-building initiatives aimed at mainstreaming sustainable infrastructure delivery in both developed and emerging economies.