Managing Choice Uncertainties in Life-Cycle Assessment as a Decision-Support Tool for Building Design: A Case Study on Building Framework

Abstract

To establish a circular economy in society, it is crucial to incorporate life-cycle studies, such as life-cycle assessment (LCA), in the design process of products in order to mitigate the well-recognized problem of the design paradox. The aim of the study was to provide means in a structured way to highlight choice uncertainty present in LCA when used as decision support, as well as to mitigate subjective interpretations of the numerical results leading to arbitrary decisions. The study focused on choices available when defining the goal and scope of a life-cycle assessment. The suggested approach is intended to be used in the early design phases of complex products with high levels of uncertainty in the product life-cycle. To demonstrate and evaluate the approach, a life-cycle assessment was conducted of two design options for a specific building. In the case study two types of building frameworks were compared from an environmental perspective by calculating the global warming potential, eutrophication potential, acidification potential, stratospheric ozone depletion potential and photochemical oxidants creation potential. In the study, a procedure named the Decision Choices Procedure (DCP) was developed to improve LCA as an effective tool for decision support concerning design alternatives when less information is available. The advantages and drawbacks of the proposed approach are discussed to spur further improvements in the use of LCA as a decision-support tool.

Design for Sustainable Public Transportation: LCA-Based Tooling for Guiding Early Design Priorities

“…In earlier design phases, it is easy to make changes, but less information is available, whereas late in the process there is more information, but it is difficult to make meaningful changes. This knowledge trade-off is especially apparent in the application of LCA [56].…”

Life Cycle Assessment under Uncertainty: A Scoping Review

“…Not only was MCS used in conjunction with other uncertainty analysis methods, but it was also used as a secondary method to handle the main methods such as global sensitivity analysis and decision choice procedure (DCP), etc. [43,57,103,108]. Table 6 provides the uncertainty analysis methods and software in the selected studies.…”

“…[107] "Choice uncertainty present in LCA when used as decision support, as well as to mitigate subjective interpretations of the numerical results leading to arbitrary decisions". [108] Wood materials volumetrically change, and the volumetric percentage of each major building material. [75] Variation in the input parameters in the life cycle inventory (LCI) analysis and the priority weights for the AHP method concerning the overall environmental impact score.…”

Dealing with uncertainties in comparative building life cycle assessment

“…uncertainties in quantities or physical properties of building materials or systems, or in the service lifetime). As pointed out by several authors, the potential environmental gains are the largest in early design phase, but uncertainties are also higher in this phase as many decisions have yet to be made [36][37][38][39]13].…”

“…The seven studies considering dependent samplings used DA or similar methods in order to compare alternatives, which were visually compared by plotting DA results in graphs [55] or in matrices [36]. Another option was to plot the distribution of impact ratios [56,57], or the distribution of impact differences [39,58,59] between pairs of alternatives. This is in line with the recommendations of Marsh et al [13] to use dependent sampling, and DA or HSM.…”