Global embodied carbon in buildings: Meta-analysis and science-based decarbonization through technological solutions

As net-zero energy buildings become increasingly achievable, decarbonization efforts have shifted toward reducing embodied carbon (EC) across the full building life cycle to meet net-zero carbon targets. However, the existing research lacks statistical analyses that quantify the potential reduction in material carbon emission achieved through current technological advancements. This study integrates meta-analysis with science-based target-setting methods, reviewing the upfront carbon (covering material production, transportation, and construction) of 197 newly built projects over the past two decades. The data are categorized into two scenarios: Business-as-Usual (BAU) and Build-with-Technology (TECH-Build). Normalization results show that current TECH-Build achieves an average 45.7 % reduction in upfront carbon compared to BAU practices, equivalent to 236.29 kgCO2e/m2 in savings. Key mitigation strategies were further evaluated, with low-carbon materials, circular economy, digital optimization, and construction management contributing reductions of up to 59 %, 40 %, 35 %, and 2 %, respectively. Using a 1.5 °C-aligned global carbon budget, we estimate that new construction must reduce upfront carbon by 12.5 % annually between 2025 and 2050 to remain within the 20.21 GtCO2e budget, converging to 17.5 kgCO2e/m2 by mid-century. Current TECH-Build performance aligns with 2029 globally and 2030 in Europe but falls short thereafter without accelerated uptake. Comparison with RIBA, LETI, and NZCBS benchmarks shows that current decarbonization strategies are technically feasible but require substantially higher market penetration to meet future targets. Overall, the findings highlight both the potential and limitations of existing technologies, emphasizing the need for adaptive, budget-aligned EC benchmarks that evolve with technological innovation on the pathway toward carbon-neutral buildings.