The case for taking action to tackle climate change is now persuasive. It is developed countries that must reduce GHG emissions most and this paper focuses on one such country – the UK. We address issues associated with the decarbonisation of the built environment and the housing stock in particular. We demonstrate the potential for significant unintended consequences and discuss the complexity involved in attempting to understand such processes. We argue the urgent need for the formation of multi- and inter-disciplinary teams with the diverse range of skill sets required to think together and to address these issues. Such teams must involve (at least) Building Physicists, Engineers, Economists, Epidemiologists, Statisticians, Behavioural Scientists, Complexity Scientists and Policy Makers. Without a coordinated and concerted programme of relevant research it is difficult to imagine how the necessary policy will be formulated and implemented effectively without the potential for enormous and irreversible mistakes.