本文以中層辦公大樓為原型，探討各種設計因子對建築結構體建材用量及碳排放量之影響。共設定18組案例電腦結構模型，依照台灣一般結構設計流程實際執行分析與斷面設計，精算混凝土與鋼筋用量，再依照本土碳排資料庫換算碳排量。分析結果發現樓層數、震區、跨距變化、靜載重及活載重皆與建材用量及碳排量有顯著正相關。根據上述因子建立建築結構體碳排量簡易評估公式，與集合住宅實際案例之比對結果顯示，本文簡易評估公式若採原型基準值則略偏低估，若採保守設計基準值則略偏保守，但誤差平均皆在5％以內，顯示本文公式可提供合理評估。

Eighteen computer structural models of mid-rise office building were analyzed to study the factors affecting the material usage and CO_2 emission. Section dimension and steel ratio were designed in accordance with the Taiwan building codes. The concrete and steel usage were calculated and then converted into the CO_2 emission with a Taiwan-based carbon databank. The analysis results showed that the material usage and carbon emission increase as the story number, seismic zone, span change, dead load, and live load increase. A rapid estimation equation is developed by including these factors. Comparison with actual residence buildings shows that the developed equation slightly underestimates the CO_2 emission. Modified equation by using the conservative design case result instead of the prototype result shows conservative estimation. Both equations have an average error lower than 5% and therefore can be considered reasonable.