Clay walls have a high thermal inertia. This means that they act as a climate buffer that creates a thermal delay in the flow of heat from the outside to the inside, absorbing it during the day and releasing it overnight. The material is especially suitable for hot and dry climates, such as that of Gando, where Francis Kéré built his first school. After years of studying abroad, Kéré returned to his home community with the intention of building this school with the same materials historically used by locals, which many originally viewed as strange, as he said in this lecture. Despite the initial prejudice, it was the combination of local materials and techniques with Kéré’s acquired knowledge that ultimately gave strength to the project.