thanks but ive just started to learn it a few weeks ago 
so, I have a few lightmass portals in the windows to channel the indirect light into the room.
Indirect light ray bounces are set to 100, indirect quality set to 10.
the exterior in this case doesnt matter too much as it is an interior demo, if I’d do exterior i would probably build it in another level so when you go in you have a different lighting setup for the room compared to the outside, so I dont have to sacrifice the look on either the outside or the inside - since its not an actual game, more of an archviz demo, it does not have to be that “seamless” regarding navigation in and out of a building. (so I think a loading screen is fine)
So as far as my knowledge goes about global illumination my bet would be that the rays are bouncing back and forth in that area, but i have no idea how to “kill them” after a few bounces as for the rest of the scene the 100 bounces look perfect