Sustainable site selection using system dynamics; case study LEED-certified project

Abstract

ABSTRACT This study establishes a dynamic modelling for site-related credits. Guidelines of the ‘Leadership in Energy and Environmental Design’ (LEED) system are used for the context and project levels under Location and Transportation (LT) and Sustainable Sites (SS) categories, respectively. The research steps are; determining site-dependent credits based on LEED project checklist and credit-weighting calculator, calculating the dependency coefficient of credits and categories, developing representative causal-effect feedback loops and a stock-and-flow model using VENSIM-PLE and testing two alternative project site locations. Studying these intrinsic relations reveals that proper site selection may earn the project 63% of total available points which qualifies it to LEED Gold certification level. The results show the dominant effect of site selection on the context and site-related credits. It also shows the latent effect on other sustainable categories; the highest impact is seen for energy-related credits (EA), followed by indoor environmental quality (IEQ), materials and resources (MR) and finally for water efficiency (WE). Comparing site-dependent credits for LEED Version 3.0 and 4.0 shows that they are less in WE and EA for the latter and more for the MR and IEQ categories. This shows that the improper selection of a project site may eventually lead to downsizing building performance. Furthermore, the proposed model establishes a dynamic predictive tracing and evaluation mechanism for the rate and pattern of point-scoring scenarios to achieve sustainability targets and level of certification. It also proposes a new datum to assess the sustainability of site locations; both in a comparative and absolute manner.