Evaluating Daylight Factor Standard through Climate Based Daylight Simulations and Overheating Regulations in Estonia

Building interiors daylighting is a crucial aspect for occupant comfort and energy efficiency. Standards and requirements exist to guarantee minimum levels of natural illumination in new buildings on the basis of different metrics. Some rely only on interiors static characteristics, others additionally take into account location climate. The main aim of the present study is to investigate the validity of the static Daylight Factor (DF) requirement of the Estonian daylight standard against more reliable climatebased daylight simulations using the approved method Spatial Daylight Autonomy. Results show the weakness of DF in predicting appropriate daylight availability of building interiors for the city of Tallinn. Evaluations of DF in relation to overheating regulation is also presented.