Mexico has invested many resources in education ever since the enactment of the 1917 Constitution, where the government committed to providing quality education to every Mexican. Investment has increased over time (INEGI, 1994), but the results have not shown the level of commitment, since Mexico is ranked 32nd out of 34 members in the 2021 OECD Education indicators report (OECD, 2021) as well as falling behind in education level and quality (CONEVAL, 2022). This study focuses on the schools by Juan O’Gorman in 1932 and the Daylight conditions. Considering his methodology and theory adapted to the historical context around him, and the uses required for the building type. This thesis centers on two typical classrooms used in the schools built by Juan O’Gorman. The main goal of this thesis is to answer the question, Do the classrooms following the Functional Modular System by Juan O’Gorman perform as an efficient place to provide education? Does it fulfill the “basic daylight needs” of a primary school? How do the schools use the Functional Modular System performance in today’s context using current international lighting standards? The analysis of the 1933 schools by O’Gorman, showed that there is a need to adjust the codes to match the geographic location of Mexico. Since the results obtained showed that the minimum required levels in sDA, UDI and ASE are met with minimum effort, but the higher thresholds are exceeded. Special attention to glare and direct Sunlight is required to prevent the negative effects of daylight in work and study spaces such as eyestrain, and veiling reflections caused by reading surfaces (Dubois et al., 2019). Further studies are required to analyze the perception of the space, and the academic performance of the users to find the possible consequences of the high glare and contrast levels found in this thesis.