Book excerpt: This book constitutes the proceedings of the 13th International Conference on Smart Homes and Health Telematics, ICOST 2015, held in Geneva, Switzerland, in June 2015. The 20 full papers and 16 short contributions included in this volume were carefully reviewed and selected from 45 submissions. They were organized in topical sections named: design and usability; assistive and sentient environments; human behavior and activities monitoring, and health IT and supportive technology. The book also contains 3 invited talks.