A Multi-Scale Consideration of Daylight in a Real Urban Context

In dense urban environments, many indoor spaces are poorly daylighted. This article presents the impact of the optical characteristics of facade elements on a set of buildings located in a historic city centre street. Climate Based Daylight Modelling (CBDM) metrics at a street scale provide accurate information on the daylight performance of buildings interiors. The results show that the daylight autonomy (DA) of dark spaces is strongly influenced by the reflectance of the facades of surrounding buildings. The radiosity method presented allows for an accurate and fast calculation of CBDMs on a large number of sensors for a multitude of facade configurations with different reflectances. More detailed knowledge on the importance and potential of light inter-reflection in a dense urban environment is presented.