Key attributes of a longitudinal study of green project delivery

If green buildings are to continue to reduce the environmental impact of buildings and improve the operating performance of facilities, it is now more important than ever that a study of key project delivery practices, like teaming strategies, contracting approaches, and incentives, be established for these projects. When the performance outcomes of these projects, like sustainable rating, final cost, project schedule and operating performance, are statistically correlated to the project delivery practices, tremendous insight is gained for owners on how to establish their team so that their performance objectives are maximized on their green project. Initial exploratory research reported in this paper confirms how scientifically challenging such a study is to pursue with rigor. There are so many potential variables that may impact sustainable performance outcomes that a quality study needs a sample size in the thousands. By necessity a large study must occur over many years and thus the design of the study is crucial due to the time that lapses between implementation and results. This type of study, often referenced as a longitudinal study, is common in more mature disciplines of anthropology and medicine, especially, epidemiology. The contributions of the paper include a set of preliminary project delivery attributes to focus on for green building projects and data collection and analysis methods for large study of green building project delivery. Copyright ASCE 2009.