Daylight in urban canyons: planning in Europe

ABSTRACT: Daylight calculations are commonly based on the daylight factor method regardless of prevailing weather conditions. While this method may be used for overcast sky conditions, it can be argued that it is not appropriate for clear skies. Furthermore, reflected sunlight from obstructions and ground is a major contribution to the illumination of buildings in orientations and at times when the sun is behind the building. A simplified calculation that takes into consideration reflected sunlight may be used for quick calculations in the initial design stages of the project. Two different set of criteria for daylight and urban planning are presented. They apply to predominantly overcast and clear sky conditions. Both, individually or combined, allow for daylight design in European climates