System Dynamic Models and their Use for Exploring Future Change

Introduction Retrofitting our current building stock and urban infrastructure is a vital part of meeting emissions reductions targets, using energy and resources in a more efficient way and creating sustainable lifestyles. However, one of the key barriers identified is a lack of appropriate modelling and decision support tools to aid long-term planning for sustainable urban retrofitting. In this respect the complexity of the built environment in cities represents a significant challenge. In recent years significant advances in ‘bottom-up’ models have allowed the development of increasingly sophisticated simulation tools for use at building and urban scales. However, such static models can by themselves tell us relatively little about the dynamics of urban retrofit transitions. This report explores the use of system dynamics in developing integrated modelling tools and approaches at different scales, through: i) the creation of a transparent and flexible building energy performance simulation model (SdSAP); ii) a prototype toolkit for the analysis of urban retrofit options at a local authority scale; and, iii) a participatory group modelling exercise carried out with a multidisciplinary group of expert stakeholders, with the objective of enhancing understanding of the challenges and long-term dynamics of systemic urban retrofit at a city-regional scale.