This article proposes a technical assessment methodology applied to rehabilitating existing school buildings. The study, of an applied nature and based on doctoral research, starts by diagnosing functional, structural, and normative deficiencies that characterize the school building stock. With six sections, the text initially presents rehabilitation’s theoretical and normative foundations, differentiating it from maintenance and retrofit. Next, the structuring of the assessment methodology, based on technical categories such as sustainability, accessibility, environmental comfort, safety, and waste management, is discussed. The critical analysis of these categories allows for demonstrating specific rehabilitation strategies. The discussion section highlights the applicability of the methodology to support public policies and technical projects, promoting the prioritization of investments and efficient building management. As a final remark, the proposed methodology contributes to the qualification of school environments, extending their useful life, adapting them to current regulations, and promoting equity in access to education. Rehabilitation, understood in this way, strengthens the role of Civil Engineering as an agent of social and technical transformation.