Dailylight simulation with framed windows

I'm running a daylightsimulation where I have an imported CAD-drawing.

My problem is how to handle my windows since they are drawn comlepete with windowframes. I know that they are excpected to be childsurfaces, in essence co-planar and not reach to the edges of my wall surface.

So far I have managed to import surfaces as polysurfaces. Windows with frames are modelled as block. I have tried to explode them to get to the individual surfaces which worked. Still I have problem with the windows pane it self being non-planar to the wall and modelled as a polysurface.

How would you go about modelling this kind of construction?

(I'm new to the Rhino Grasshopper world)