In housing BPE, a model is a simplified description of a real system or process to assist calculations and predictions of housing performance. Having set out a theoretical background to housing BPE, this chapter describes how 'real world' action research can feed back into the housing design and build process. Dynamic modelling of predicted housing performance requires complex calculations to account for all the variables over time. Building Information Modelling is a new horizon for housing BPE, allowing all building information to be fully coordinated within a single computer-generated building model. Large housing developers often prepare a careful induction process, during which personnel meet with the new inhabitants, before, during and after handover, to explain how the home works. Housing BPE is most effective when incorporated into the building process from the beginning, but it can be useful when introduced at the commissioning stage in any newbuild or retrofit project.