BB your words are like the law for me, you are a guru of Poser (no offense to all the others who are trying to help)

Compared to the first rendering of this post, I added externally to the windows (on right and left) a light emitter.

I also added a little flare to the floor, seems to be a bit more realistic.

I used BB Glossy for wood and everything seems much more realistic.

I always render at low resolution, so the imperfections are due to settings

• first problem:  the light emitters on the outside of the windows are visible in the reflection on the floor, there is a solution for this ?

many thanks

Poser Pro 2014 SR 1 on Windows 7 64 bit
I use IDL, Gamma Correction and EZSkin for all final renders.