The first thing I’d look at is the lighting, which seems overall too dark. Sunlight I suggest would be from left to right to illuminate the front and cast probably more interesting shadows.
Try that and see how it improves it, as it’s a basic start point really.
Once you have the lighting looking plausible then add stuff…entourage/chaos, however you term it. Benches/seats, exterior lighting, plants/flowers/other appropriate objects to break up the straight lines.
Put some lights on inside, leave a door or window open and furnish the rooms if they can be seen at all. Blinds on windows.
Vary the texturing as much as possible, using grunge maps etc, just to break up the colouration/tones.
Use an hdr for some more background interest, as now it’s empty grey, or fill it with random far foliage etc., depending on what the actual site is like of course. 
Thank You.
I can´t change the light direction because this exactly what my client want. : (
Ok, it’s common for the client to go against what is arguably a better choice, though I would in any case do an alternate version which ‘should’ convince them, after the other things are addressed
Hi @piotrus3333 ,
what do you mean or what is the Workaround?
just use filmic tonemapping layer in VFB.
magnific will do a lot of heavy lifting if you let it. Even if it changes parts of the building, you can still see what it has done to tie the image together better.
edit: plus some PS adjustments
I guess saving an image properly before any photoshoping/magnifiqueing saves time, right?
@Rickmc care to share your layer stack from VFB?
OP is asking about getting realism in VRay and not for a completely different workflow/tool(thats you have to also pay for). There is plenty to be learned about what makes an image suspend disbelief, which you can still send to AI gen if desired. And typically your AI gen will be better if you give it an already good input - it will also be more accurate and you don’t have to crank yoru sliders or deal with wired fractal issues.
Realism for exterior almost always comes down to camera and lighting. In the OP shot the camera is floating arbitrarily(not sure what new or extra information this is giving us over an eye level shot). The lighting is impossibly high, nearly over head. The sun never looks like that. There is also no atmospheric falloff(atmospheric perspective).
If its what your client wants you have to explain to them that there is a tradeoff. They can either have unrealistic camera and lighting or a realistic image, not both.
I disagree.
