This book constitutes selected papers of the 19th International Conference on Computer-Aided Architectural Design Futures, CAAD Futures 2021, held in Los Angeles, CA, USA, in July 2021. The 33 revised full papers presented were carefully reviewed and selected from 97 submissions. The papers are organized in topical sections on past futures and present futures: research and pedagogy; past futures and present futures: aesthetics and ethics of space; architectural automations and augmentations: design; architectural automations and augmentations: fabrication; architectural automations and augmentations: environment; architectural automations and augmentations: spatial computing.