Alexandre - nice work! I think the 4th image - corner of blue tile and glass curtain wall - is the most convincing, and feels most like space, but I really like the last image where the reflective caustics from the glass wall are illuminating the grass ground plane! That's a very cool effect! You might take a look at this post:
http://www.maxwellrender.com/forum/viewtopic.php?t=996
I think you might also be experiencing the problem with direct sunlight penetrating glass surfaces to illuminate interiors. I've had this problem too, apparently it's related to the overall dimensions of the scene...
Imua!, F