Recommended doors + windows area (% of floor area) in a school class must be:

Healthful school environment: Minimum recommended standards:- 1 classroom- <40 students Doors and window: Doors and window area > 25% of floor area Per capita space > 10 sq. feet Desk- minus type Natural light from left side 1 urinal per 60 students 1 sanitary latrine per 100 students.