A daylight simulation tool for urban and architectural spaces—application to transmitted direct and diffuse light through glazing

The paper describes new improvements in S , a set of numerical models for the simulation of natural light in both the urban morphologies and the indoor architectural spaces which is developed in our laboratory. This tool takes into account the direct solar and the diffuse sky luminous energies for the evaluation of luminance, that can be computed on the real surfaces of the environment (ground, walls), or on a false working plane. The tool allows the computation of some classical parameters (such as the illuminance levels on a working plane, the daylight factor), but makes it possible to get other informative descriptors. After a brief presentation of the tool and its general features, we will specially focus on the model of the physical behavior of light and our original way to manage with multiple transparencies. This specific focus makes it possible to take into account some complex cases: intermediates spaces (atriums, covered galleries, glazed corridors), multi-layered fenestration systems, or semi-transparent screens (vegetation).