Education was and will remain an indispensable tool for the progress of nations. Therefore, strategies must focus on ensuring that children have access to education for all. However, as the demand for education continues to rise, it has become imperative to create schools with flexible building systems that meet the evolving needs of students and teachers. Not only do these buildings accommodate a larger number of students, but they also provide learning environments appropriate to pedagogical standards, considering factors such as rapid construction, flexibility, and sustainability. The study proposes the concept of a modular building unit, which allows its implementation in different building systems, to achieve flexibility, speed, and efficiency. To clarify the advantages of modular units, an illustrative model was proposed for the flexibility of designing school buildings in patterns that keep pace with the variables of most sites, or as in cases of expansion in existing schools. The study concludes that the advantages of using this method in buildings allow for providing an educational environment suitable for standards at an appropriate time.