Calado2,
The scene is a little dark to give a true critique. The image and modeling looks good except for how dark it is. Here is what jumps out at me: the scene is a little sparse, more lived in look could be achieved with more furniture or items. The marble cap and stairs look like they are made from on giant slab, which would be difficult to come by let alone install, so I would make it several slabs breaking it up and varying the texture slightly so it would look more realistic. It may be that they are several pieces, if so I would chamfer the edges slightly to make it obvious. The style currently is a little contradictary, the lack of moldings and style of furniture makes it look like a modern interior, yet you have classical columns etc. in it. I think if you went for a transitional style with simple moldings etc. it would add to the scene and carry off the design a little better.
It is a nice scene, just a coupel items I noticed

If it was lightened up a little we could see more of what is going on and perhaps give better input. the painting on the wall is a nice touch. Hopefully you will register and post more work and comments. Look forward to seeing more from you.