The ENERGISE project makes an important contribution to understanding what role households can play in transformations towards using energy more sustainably in domestic spaces. This handbook provides an overview of the project from theory development, through to practice, and further reflections on lessons learned for policy, research and practice. Throughout the project, consulting with multiple stakeholders, we have drawn on cutting-edge social scientific methods and techniques to help us develop a better understanding of how and in what way people use energy, with specific focus on thermal comfort (heating homes) and cleanliness (washing laundry). We began by analysing over 1000 sustainable energy consumption initiatives toward developing innovative typologies and informing the empirical component of our project. We then adopted a ‘Living Lab’ approach working with over 300 households across 8 European countries. Through the ENERGISE Living Labs, we engaged households in participatory research in order to challenge social norms and habitual practices tied up with energy usage, with the overall aim of adopting more sustainable practices.