ABSTRACT
Daylight data are essential at various levels during the design process and performance assessment of buildings. Basic sky data, in the form of simple descriptions, make an architect aware of overall conditions with respect to location of the site. The discussion in Chapter 2 about the differences between southern and northern European skies has already been shown to be important in terms of an appropriate architectural response. More detailed information, in the form of sky brightness distribution curves or daylight availability data, gives basic quantitative details that can be used in simple analyses of design options. Accurate data and techniques to determine sky conditions are important to judge the final design’s performance in terms of both visual comfort and energy use over time. It is clear that the use of daylight to offset the need for artificial lighting can result in important energy savings and reduced carbon dioxide emissions, particularly in non-domestic buildings such as offices, libraries, schools, etc. Because of the dynamic nature of daylight and the resultant variations of energy and lighting conditions, daylight information is required that is climatically and temporally accurate and easily available in order to assess detailed design solutions.
