Make carbon a pass/fail item at project decision gates: a governance framework would convert embodied-carbon assessment from after-the-fact reporting into enforceable criteria at stage-gates, concentrating scrutiny early where design choices most affect whole-life emissions.

The construction sector accounts for a substantial and rising share of global carbon emissions, and as operational efficiency improves, embodied carbon is becoming the dominant contributor to the carbon profile of new built assets. Embodied carbon is largely determined by decisions taken early in the project lifecycle, yet the governance mechanisms that control project progression rarely treat carbon as a formal decision criterion. Carbon accounting remains predominantly retrospective, applied as an assessment exercise after key design and procurement choices have been fixed, which constrains its capacity to shape outcomes. This paper addresses the disconnect between whole-life carbon assessment practice and stage-gate project governance. It develops the Carbon-Driven Decision Gates framework, a conceptual model that embeds embodied carbon accounting into the decision gates that govern transitions between lifecycle stages. The framework reconceives the project gate as a carbon control point, specifying gate-level carbon budgets, threshold criteria, accountability roles, information requirements, and decision outcomes. Drawing on project governance theory, stage-gate decision logic, and real options reasoning, the paper advances six propositions linking gate-level carbon control to improved and more reliable carbon outcomes. The framework contributes a governance-centred account of carbon management that repositions embodied carbon from a measured attribute to a governed variable, and it offers project organisations a structured basis for operationalising carbon accountability across delivery. Implications for theory, practice, and policy are discussed, alongside an agenda for empirical validation.