Comparing Multi-Criteria Decision-Making Methods to Select Sustainable Alternatives in the AEC Industry

Researchers and practitioners in the Architectural, Engineering, and Construction (AEC) industry have been incorporating sustainability (environmental, social, and economic) aspects into decision-making, e.g., designers have selected materials with sustainability in mind. Many have used multi-criteria decision-making methods, appearing to assume that all methods are equal or that the selection of a method does not matter. In this study we argue that methods matter. We see two issues pertaining to method selection. First, what are necessary characteristics of `viable' methods and, correspondingly, what are characteristics that disqualify methods? Second, for those methods screened for viability, what differences between them make some more suitable than others for different applications? This paper focuses on the first issue, specifically on one characteristic that appears to us to govern viability: factors should not be weighted. We compare the Analytical Hierarchy Process (AHP) with Choosing by Advantages (CBA), using an example and argue that AHP does not meet viability requirements.