Book excerpt: Designing Cities with Children and Young People focuses on promoting better outcomes in the built environment for children and young people in cities across the world. This book presents the experience of practitioners and researchers who actively advocate for and participate with children and youth in planning and designing urban environments. It aims to cultivate champions for children and young people among urban development professionals, to ensure that their rights and needs are fully acknowledged and accommodated. With international and interdisciplinary contributors, this book sets out to build bridges and provide resources for policy makers, social planners, design practitioners and students. The content moves from how we conceptualize children in the built environment, what we have discovered through research, how we frame the task and legislate for it, and how we design for and with children. Designing Cities with Children and Young People ultimately aims to bring about change to planning and design policies and practice for the benefit of children and young people in cities everywhere.