<p>Climate change is a growing threat that requires collective action to alter the technologies, consumption, and production methods. Circular economy aims to enhance resource efficiency and reduce waste, but its synergies and antagonists with climate mitigation and innovative policy approaches remain unknown. This study illustrates the antagonisms and synergy paths between climate mitigation and circular practices via a systematic review of European policy levels. It uses European directives as proxies for Circular Economy and Climate Mitigation policies and analyzes 197 relevant directives quantitatively and qualitatively. Quantitative analysis was used for the official European EuroVoc classification and text mining of keywords relevant to Climate Mitigation, Circular Economy, and construction materials. The qualitative analysis involved an expert analysis of a subsample of 48 key directives and interviews with EU-wide policy and industry representatives. The policy framework suggests that synergies are more common than antagonisms in promoting energy efficiency in recycling processes, which are energy-intensive and may increase transportation requirements. However, extended product life cycle measures can also be used to link these measures. Finally, the study provides practical implications and recommendations for policymakers associated with Circular Economy and Climate Mitigation policies as well as their interrelationship in terms of construction materials, offering a roadmap for effective policy design and implementation. </p>