The country I am in is building many residential communities every year. A typical community has well over ten detached buildings, from 6 stories to over 30 stories. The applicable code requires that the south-facing windows on the 1st floor shall receive no less than 2 hours of sunshine at the window sill on the winter solstice. Therefore, a simulation is usually needed to verify this since buildings have shadows and they change during the day and it is quite complex.