Studies on building carbon emissions focus mainly on the materialization phase of life cycle, as carbon emissions in this stage is intensive and high. This paper proposes a simplified model to calculate embodied carbon emissions in building design stage by conducting a process-based inventory analysis of carbon emissions from materials used in 129 residential buildings, 41 office buildings, and 21 commercial buildings during materialization phase. The results indicate that average carbon emissions per unit area from building materials used in residential buildings, office buildings, and commercial buildings are 514.66 kgCO₂e/m², 533.69 kgCO₂e/m² and 494.19 kgCO₂e/m²,respectively. Besides, ten kinds of building materials (namely, steel, commercial concrete, wall building materials, mortar, copper core cables, architectural ceramics, PVC pipes, thermal insulation materials, doors and windows, and water paint) constitute 99% of total carbon emissions in all three types of buildings. These materials are major carbon emissions sources in materialization phase. Thus, embodied carbon emissions can be significantly reduced by limiting the amount of these materials in architectural design as well as by using environmental friendly materials. 建筑物化阶段的碳排放时间集中、排放量大，因而成为建筑生命周期碳排放研究的聚焦点。本研究通过界定建筑物化阶段碳排放的系统边界，对建筑案例进行LCI分析，确定碳排放比例最大的建筑材料，以简化建筑物化碳排放的计算，在建筑方案设计中快速计算建筑物化阶段碳排放量。本文利用基于过程的清单分析方法，研究了129栋住宅建筑、41栋办公建筑和21栋商业建筑的物化阶段的建材碳排放量。结果显示，住宅、办公和商业建筑物化阶段的建材碳排放量按面积加权平均值分别为514.66 kgCO₂e/m²、533.69 kgCO₂e/m²和494.19 kgCO₂e/m²。三类建筑中钢、商品砼、墙体材料、砂浆、铜芯导线电缆、建筑陶瓷、PVC管材、保温材料、门窗和水性涂料等十类建材的碳排放量均达到了建筑物化阶段总建材碳排放量的99%，是物化阶段碳排放最为主要的建材。在建筑方案设计中控制这十类建材的用量，选用低环境影响的建材产品就可以有效降低建筑物化阶段的碳排放。