Volkan Arslan, Şefik Hakan Papila
Despite the ambitious 2053 net-zero targets, the Turkish construction regulatory framework remains predominantly focused on operational energy efficiency, leaving a critical hidden carbon gap regarding embodied emissions. This study evaluates the misalignment between national codes (BEP-TR) and international whole-life carbon principles by analyzing the material-related carbon gap of a typical residential building in Zonguldak. Using verified Bill of Quantities (BoQ) data, a scenario-based embodied carbon assessment was conducted across three trajectories: Pessimistic (Business-as-Usual), Baseline (Standard Practice), and Optimistic (Low-Carbon Transformation). The results reveal that current regulations ignore 249.0 kgCO₂e/m² of upfront embodied carbon in a standard code-compliant building, increasing to 256.0 kgCO₂e/m² when scenario-based end-of-life emissions (C1–C4) are included. The structural system alone accounts for 71.4% of these unregulated upfront emissions. Scenario analysis demonstrates an approximately 48.0% reduction potential between the pessimistic and optimistic supply-chain trajectories, confirming that material selection is as critical as design geometry in reducing embodied carbon. Notably, the Optimistic Scenario indicates that utilizing existing low-carbon technologies could reduce the upfront embodied carbon by 32.2% compared with the baseline without altering architectural practices. However, a readiness paradox exists in which advanced materials produced for EU CBAM compliance are not sufficiently incentivized in the domestic market due to legislative inertia. This study concludes by proposing a phased regulatory roadmap that begins with embodied carbon disclosure and progressively integrates mandatory WLCA reporting, thereby aligning the Turkish construction sector with the EU EPBD and improving economic resilience against future carbon taxes.