Comparative assessment of daylight availability in high-density residential area: a case in Harbin

Urbanization has substantially increased the populations of some giant cities in north-east China. More and more high-density residential areas were developed. The new situations have actually brought negative impacts on urban environmental quality. Daylighting is regarded as one of the most crucial indicators for the qualities of a living environment. It is very essential to investigate the daylight availability in the new high-density residential areas. This study introduced two different models to assess urban daylight availability. The static model (daylight factor) was simple and easily adopted, but failed to respond to climate-based conditions. Based on DC (daylight coefficient) and Perez sky function, the dynamic model can dynamically achieve annual daylight level profile using real weather data. The daylight levels at building facades in a residential plot of Harbin have been analysed by the two models. It has been found that the dynamic model is more practical and efficient than the static model, especially for the daylighting assessment in a complicated urban area. The conclusions would be of great benefit to constructing energy-efficient and low carbon city in China.