Carbon, Control and Comfort is a three-year collaborative research project aiming to engage users in the design of control systems that they like, that allow them to create the comfort conditions they want and which, through using the technology and fabric of their homes more effectively, reduces their energy use. This presentation will discuss how occupants' comfort practices impact upon energy use and the socio-technical, usability, design and ethical factors which could inform the development of new devices or systems that enhance and promote energy reducing comfort practices.