Abstract
The proposed method for calculating natural lighting in school classrooms makes it possible to more accurate calculate the illumination, taking into account the complex geometry of the premises and the characteristics of the cloudy sky. It is known that the presence of natural light strengthens the immune system and the psychological state of pupils. Taking into account the distribution of brightness across the sky makes it possible to more accurately calculate the luminous flux entering the room. The results of calculations are presented in the form of graphs, diagrams and visualizations that make the information clear and understandable. It is shown that taking into account the uneven distribution of the brightness of the firmament in cloudy skies makes it possible to more accurately calculate the luminous flux entering the school classroom through window openings and gives higher results (at least 10% than the calculation using the traditional method of SP 367.1325800.2017 “Residential and public buildings. Rules for the design of natural and combined lighting”).