Sustainability and the built environment: A metric and process for prioritizing improvement opportunities

A quantitative model of built facility sustainability was proposed as a solution to the problem of prioritizing improvement options for increasing the sustainability of built facilities. Stakeholder Satisfaction, Resource Base Impacts, and Ecosystem Impacts were identified as a set of parameters to define the sustainability of systems on a technological scale. These parameters were corroborated via a content analysis of 83 definitions from the sustainability literature. The parameters were incorporated into a construct of system sustainability represented as a three-dimensional decision space. The three parameters of sustainability were operationalized in terms of built facility systems, resulting in a set of variables meaningful to facility decision makers that could be measured directly or estimated using available data. Logical relationships were specified among the variables to create a quantitative model with behavior matching constraints and objectives from the literature. A process for applying the model to prioritize facility improvement options was derived from classical decision theory, resulting in a vector-based representation for comparing options in terms of their improvement to the sustainability of a facility. A case study was used to demonstrate the model, and subsequent performance analysis of the model's behavior included comparison of expected results with model outputs, sensitivity analysis, and analysis of the mathematical properties of the vector representation. Findings from these analyses suggest that the model provides the capacity to discriminate among improvement options in terms of their relative sustainability. Implications for model refinement are discussed as areas for future research.