ContextSrf vs WindowShade

Hi guys

I am trying to run some energy analysis with shading. Based on my results I see that ContextSrf does not make ALMOST any difference in solar gains or indoor operative temperature even though all windows were "covered" by shading (look at the example file, red group, the right one). Same goes for the surrounding buildings. They should cover much more solar gains than they do.

Using the EPWindowShade component makes a difference but the geometry is to limited for my purpose. If just the contextsrf component works I am good to go, otherwise I am really stuck. Please help me!!!