Thanks Genny. It really helps having other people take a look. It is so easy to get engrossed in the detail of the scene that one looses the bigger picture. The critique is appreciated.

I see your point about the outside light not having much of an influence. The effect I'm going for is to have the exposure set correctly for the indoor lights. The inside walls should be white or almost white. The window area should then be overexposed, but by how much is one of my problems.

The indoor area lights are using a blackbody set to 7000K. And just to complicate things a bit more: they have linear decay with the intensity on the BB set to 15.

There is no direct sunlight coming in. There is only reflected light from a partially overcast sky (IBL). I was relying on the IBL/portal light to give the correct outside color temp (8000-10000K) but it appears not to be the case. Can a BB plugged into the environment of the portal light be a possible alternative?