Confronting issues of global climate change will require creative approaches to energy consumption across a range of human activities. This design case looks at the evolution of a physical/digital hybrid board game that we created to encourage families to reflect on household energy consumption and environmental sustainability. Design in this context was particularly challenging due to the nature of household heating and cooling systems, which tend to be opaque and difficult to understand. Our challenge was to employ game mechanics to help build up interest, awareness, and understanding of heating and cooling systems, while at the same time providing an enjoyable and engaging activity. Through many rounds of playtesting and interviews, we converged on the design presented here. We start with a conceptual framework describing modern energy practices, after which we describe the game design and reflect on its strengths and weaknesses.