Bridging Scales and Methods: A Systematic Review of Mitigation Pathway Modeling for Germany’s Building and Construction Sector

The building and construction (BC) sector is key for climate mitigation due to its high greenhouse gas (GHG) emissions, long-lived assets, and cumulative life-cycle effects. This study presents a systematic review of 109 scientific and policy publications on GHG quantification and modeling of mitigation pathways for Germany’s BC sector, covering economy-wide and building-level approaches. The focus on Germany reflects the availability of a comprehensive statistical framework, including national GHG inventories, environmental-economic accounts, and building stock typologies, enabling cross-scale analysis. The findings show that existing approaches offer complementary perspectives but remain methodologically fragmented across scales and system levels. Top-down models align with national inventories, carbon budgets, and supply-chain emissions at aggregated sectoral scales and are primarily dominated by operational energy perspectives. Whereas bottom-up approaches resolve technological detail, stock dynamics, and embodied emissions at the building and material levels, they are often based on static typological representations and lack consistency with carbon-budget logic, sector definitions, and inventory structures. Consequently, mitigation pathways exhibit structural mismatches between targets and carbon budgets, between system boundaries and life-cycle coverage, and between sector- and building-level metrics. This review, therefore, defines key requirements for hybrid frameworks, including consistent sector definitions, life-cycle-based boundaries, carbon-budget alignment, and the integration of stock dynamics with economy-wide accounting.