在公共工程專案之規劃階段(包括可行性研究與綜合規劃)，不同設計方案的審議，經常必須仰賴所估算的專案經費(概估或概算)做為判斷準則。近年來，建築資訊建模(BIM)技術已逐漸普及，並且將其運用至成本估算上，但目前主要仍是著重於細部設計階段的細估，而本研究擬於規劃階段依據可取得的設計資訊下建立BIM量體模型，並擷取所需數量計算之參數，輔助公共工程產出概算，以利進行經費審議。研究結果顯示，在可行性研究階段具有極為有限之設計資訊下，大地工程相關成本項目之數量計算，可透過量體元件參數的協助；結構工程部分則透過樓板元件之面積進行數量計算；裝修工程部分則須透過不同量體元件之參數進行估算。而在資訊較為增加的綜合規劃階段，大地工程部分之數量計算，同樣可透過量體元件參數之協助；結構工程除透過樓板面積進行鋼筋與模板之估算外，此階段可由粗略柱樑板牆等元件之體積，直接估算混凝土之數量；裝修工程部分則主要是透過房間元件進行數量計算。整體而言，運用BIM 數量計算輔助公共工程之概算應是可行，值得進一步發展。

In the planning stage (including feasibility study and general planning stages) of a construction project, the review of various design scenarios is often based on the estimated project costs. Recently, building information modeling (BIM) technique has been used to support detailed cost estimations in the detailed design stage. Focusing on the planning stage, this study develops a BIM model (with level of details 100 or 200) to conduct quantity takeoffs (QTO) for supporting conceptual cost estimations and facilitating the budget review for public construction projects. The results show that, in the feasibility study stage with little design information available, the room objects and floor objects are used to support the QTOs of geotechnical and structural engineering cost items, respectively. Rather, different BIM objects are utilized to perform QTOs for decoration cost items. In the general planning stage with additional design information available, the room objects are also used for the QTOs of geotechnical engineering cost items. The floor objects are applied for the QTOs of reinforcing rebar and form cost items, while the volumes of various structural objects (i.e., columns, beams, slabs and walls) are directly applied to conduct QTOs for concrete cost items. Meanwhile, the room objects are applied to carry out the QTOs for most decoration cost items in the general planning stage. Overall, applying BIM's ability in QTO to support conceptual cost estimation for public construction projects is feasible, deserving for further research and development.