Uncertainty Analysis of Life Cycle Energy Assessment in Early Stages of Design

During building design and especially in early stages, important decisions influencing the lifecycle-based energy demand of buildings are made. Life Cycle Energy Assessment (LCEA) is used to evaluate this energy demand already in early stages of design. However, at that point, the building design and the related information can quickly change and are subject to potentially large uncertainty. This uncertainty in building information influences the LCEA and therefore decisions taken by the designer. Due to the uncertainty, it is difficult to distinguish between the performance of different design variants to decide for the best option. This study presents a method to perform LCEA and to assess and consequently strategically reduce the influence of uncertainties in buildings’ information on the LCEA in early design stages. Uncertainty analysis is used to assess the influence of uncertainty on LCEA and to prioritize decisions to reduce uncertainty. The method is embedded in a multi-Level of Development (LOD) modelling approach covering the development of the building during the early stages of design. The method is applied to seven different building shapes as a proof of concept. It is concluded that the method renders valid results to assess the project-specific uncertainty in LCEA results.