Developing policy for the reduction of the carbon emissions due to buildings requires models for energy usage that incorporate social, behavioural, and environmental factors in addition to the physical properties and technical specifications of the buildings. Marked parallels exist with some of the more intractable public health issues, such as rising levels of obesity. Recently, health researchers have recognized the importance of taking a broader life-course approach to epidemiology in order to examine the degree that long-term health outcomes are set in early life and the extent that these may be mediated or mitigated by subsequent growth and development, as well as by intervention strategies. Life course epidemiology as applied in building science, where energy usage is treated as analogous to poor health outcomes, provides an alternative approach for the construction of causal models that allow for complex interactions between social and technical factors as well as long term effects. It can provide a useful framework for the successful management and analysis of longitudinal studies and may prove particularly effective in identifying the type, timing, and targeting of intervention strategies to produce optimal outcomes in terms of absolute reductions of carbon emissions and resilience of building performance to external stresses, such as those imposed by climate change. An example based on a study in Milton Keynes (London), which is currently in progress, is used to illustrate the way causal models may help elucidate the complex interactions between factors that influence energy usage
