A Causality Analysis among Architectural Design Decision Factors in the Early Design Stage - focused on Reduction of Cooling and Heating Loads in Energy BIM Simulation -

Energy BIM 기반 초기 건축 단계의 설계결정인자 간 상관성 분석 - 에너지성능평가의 냉난방부하 절감을 중심으로 -

BIM records all the data of buildings from the early design stage and, therefore, has the advantage that it can actively cope with energy simulation feedback and design change with development of design stages. However, preparation of simulation based energy performance assessment system and development of BIM based low carbon design technique are still unsatisfactory. For greenhouse gas mitigation and energy saving in the architectural sector, applying of BIM based_low carbon design technique is required from the early design stage. However, as the research areas are limited to sub-segmented topics, it is difficult for designers to establish grade of rank of low carbon design technique required for application in design planning. This study attempts to analyze grade of rank and correlation among design techniques affecting building energy performance. As targets of experiments, the study selected tower buildings, which are favored recently as business facilities with huge scale, massive energy consumption and big impact on the surrounding environment. The study analyzed result values yielded from different shape, scale, slenderness ratio, window-to-wall ratio, and solar orientation of the tower buildings. Through the experiments, the study found that the component having the biggest impact on building energy performance is window-to-wall ratio(WWR) followed by slenderness ratio, envelope area and solar orientation. The influence of WWR is the biggest with 81.2% among the design components. Smaller WWR makes bigger change range of heating and cooling loads. Therefore even small change can have significant effect on energy performance. Also, In the same total floor area, slenderness ratio closer to 1:1 is more advantageous for HCL. Besides, even with the same ratio of lateral to longitudinal length, relatively long mass in the direction of East and West can increase energy performance up to 6.4%. Then, the study drew out correlation and grade of rank among different design techniques. Based on the data, energy saving can be achieved from the early stage of architectural planning. The architects also can maximize energy performance efficiency by considering and applying grade of rank of low carbon design technique in design planning. Besides, development of guidelines on Energy BIM would reduce confusion in the decision making process and design modification in development stages of design.