On validating predicted shading duration in built-up areas

We present a prediction model of shading duration in complex building structures. The model is based purely on the laws of maths and physics, with no conventional values, standard figures or hypotheses. We checked the predicted shading times by observing the shading periods in the areas surrounding four high-rise buildings in Berlin: our figures were in line with predictions, within the expected margin of error. This margin arises mainly from rounding the coordinates for both the building's cubature and the position of the observer to the nearest whole metre. Hence the calculation model presented here is not used to visualise building shadows for shading studies, but instead for a precise, validated calculation of shading duration at specific reference points based on a 3-D building model which is as quick and easy as possible to generate. This can be used in existing scenarios, as well as in planning new builds and renovations. The ProShad prediction model is also used to calculate shading duration around building complexes as a three-dimensional matrix, so that horizontal and vertical sections through the shading (duration) area can provide a comprehensive overview, for example as ground shading maps or with facade shading shown as isosurfaces at intervals during the shading period.