BIM-based preliminary estimation method considering the life cycle cost for decision-making in the early design phase

Prediction of construction cost and life-cycle cost through preliminary estimate is very important for the economic decision-making in the early phase of building projects. However, the conventional preliminary estimate has a high error range and low reliability because it relies only on the basic information of projects. In addition, the consideration of the life-cycle cost of the building is insufficient, causing problems such as budget shortage, inaccurate budgeting, and life-cycle cost increase. In this study, we propose a method of preliminary estimate based on BIM below the level of detail 2 and actual construction cost data to support the decision-making in the early design phase. To verify the proposed method, a web-based prototype was implemented and applied to three test cases. The range of error rate for three test cases was 1.93-7.16% (average error rate: 5.18%). It satisfies the criteria (−30% ~ +50%) of the "American Association of Cost Engineering". As a result, the feasibility of the proposed model was validated. It is expected to be utilized as useful information in the decision-making occurring in the early design phase, and this allows for a rapid economic review of the design alternatives, a reduced LCC, and a shortened decision-making time.