Optimization model for sustainable materials selection using objective and subjective factors

Materials selection is an area where designers can have a significant impact on the sustainable performance of a building. Objective factors such as cost constraints, design considerations, and environmental requirements can play a role in the selection of materials. However, there may be subjective factors that could also impact the selection and affect the achievement of sustainability goals. In order to help decision makers with the selection of appropriate materials, this study proposes a mixed integer optimization model that considers objective and subjective factors. Design, budget, and the number of points achieved under the Leadership in Energy and Environmental Design (LEED) account for objective factors while subjective factors comprehend user-based perceptions. An instrument further validated through a factor analysis approach is developed to measure perceptions of product sustainability in an attempt to capture subjective factors. To illustrate how objective and subjective factors influence decision making, this paper presents two cases of a building in which materials are selected using the optimization model proposed.