This study compares Choosing By Advantages (CBA) and Weighting Rating and Calculating (WRC) as Multiple Criteria Decision Making (MCDM) methods in how they support collaboration in groups, particularly pertaining to design decisions involving sustainability factors in architecture, engineering and construction industry. This study is based on an experiment done with 15 practitioners, where they formed 5 groups of 3 people each. The experiment used multiple baseline testing (MBT) and all groups made 12 decisions. The initial decisions were made using the WRC method and later, in a staggered manner between the fifth and ninth decision, the groups were taught to apply the CBA method. The CBA method is considered to be the intervention in the experimental design. Four dependent variables were analyzed: (1) time to reach consensus, (2) satisfaction with the final decision, (3) personal frustration during the decision, and (4) perceived frustration from others during the decision. The results showed with statistical significance that CBA was faster than WRC for reaching consensus and presents less personal and perceived frustration during the decision. The results do not show statistical support in favor of any method regarding satisfaction with the final decision. (C) 2016 Elsevier B.V. All rights reserved.