This book explores the role of architectural design in Colombia's peacebuilding process following the 2016 Peace Agreement between the national government and the FARC-EP guerrilla. It examines how architecture can act as a catalyst for social transformation, territorial belonging, and autonomy in rural communities historically affected by the conflict. Through a qualitative, multi-method approach grounded in participatory action research, the study develops a theoretical model of architectural design for transitions, applies it to case studies in San José del Guaviare-a region emblematic of Colombia's post-conflict dynamics-and formulates practical design tools to support peacebuilding. By analyzing projects such as the Development Programs with Territorial Focus (PDET) and the Territorial Spaces for Training and Reincorporation (ETCR), the research identifies both achievements and challenges in the implementation of built interventions. The findings highlight that effective architecture for peace must transcend technical problem-solving to integrate localized, participatory, and adaptive practices that strengthen community agency and ensure the sustainability of peace initiatives. Ultimately, the book positions architecture as an essential instrument in Colombia's transition toward peace, emphasizing the need for context-sensitive methodologies that interweave design, social justice, and the non-repetition of violence.