02338nas a2200229   4500000000100000008004100001260013000042653002200172653001600194653001300210653001500223653001500238100001800253700001500271700002100286245006600307856008300373300001400456490000600470520161000476020002202086       2013                            d  c09/2013bSolar Energy and Building Physics Laboratory (LESO - PB) Ecole Polytechnique Fédérale de Lausanne (EPFL)aLausanne10abuilding envelope10adaylighting10aradiance10areflection10asimulation1 aYang Xiaoming1 aLars Grobe1 aStephen Wittkopf00aThe assessment of daylight reflection from building envelopes  uhttp://infoscience.epfl.ch/record/190601/files/CISBAT2013_proc_Vol2_online.pdf  a1011-10160 v23 aBuildings could influence surrounding microclimate with their envelope designs. Reflective surfaces on the building envelopes could reflect daylight to the neighbourhood and cause problems such as glare and overheating. For the surrounding drivers, pedestrians and building occupants in the area, the reflected sunlight from the building envelope becomes the bright spot in their view which results visual discomfort or impairment. For building envelope designs, it is important to analyse the effect of daylight reflection to the neighbourhood at design stage. This could reduce the risk of environmental problems and minimize the consequences cost after construction.
A software tool to evaluate the reflected daylight from building envelopes has been developed. It is implemented on parametric design platform GRASSHOPPER using RADIANCE as background simulation engine. As shown in the case study, using the tool, the form of the assessed building envelope could be analysed and the critical areas around the assessed building including roads, pavements and façades of neighbouring buildings are examined for potential concentration of reflected daylight. Rich information is recorded for the critical areas: annual reflected solar radiation, period with irradiance value above threshold, origin of the reflected daylight on the assessed building envelope, etc. This information could help designers to optimize the form of the envelope and make façade material selection. The tool shows potentials for architects to understand the impact of their designs and avoid potential environmental problems.  a978-2-8399-1280-8