Just musing the practicalities of this...   On a long walk around the village I noticed that most properties built over a 100 year time span have rough cast concrete window cills and this includes new heritage houses that were build around 10 years ago under the regime of a very strict conservation officer. The rough cast cills are typically 1 brick high with a shallow gradient for water run off and are painted in the same colour as the window frame.   Would this type of wind