This book contains the proceedings of the 17th KES International Conference on Sustainability and Energy in Buildings 2025 (SEB2025) held in Catania, Italy, during September 17&19, 2025, organized by KES International. The conference attracted submissions from around the world. Submissions for the full-paper track were subjected to a blind peer-reviewed process. Only the best of these were selected for presentation at the conference and publication in these proceedings. It is intended that this book provides a useful and informative snapshot of recent research developments in the important and vibrant area of sustainability in energy and buildings.