Hi Sanja, I feel your work lacks any kind of realism if I can be honest, it reminds me of something that you would see in 'The Sims' or maybe this is your style, if so I appologise.
The House - I feel you could spend a little more time on the modelling as I cant really see any detail other than Cylinders and Rectangles, also I dont fully understand what is happening with the roof (Are there windows on there?).. In terms of materials, the brick texture is way too repetitive, you may need to edit in photoshop before applying to wall, this can make a big difference.
Foilage - I would try and mix the foreground plants and trees up, try using nuemrous models rather than the 1, and also I would not recommend using the same model and just adjusting the scale (Never really Works)
Lighting - I would recommend adjusting the light from a different angle, an angle that will show the house off the best with shadows casting from and onto it. Maybe turn the power up also.
Windows - I think you have made a good attempt at these window reflections but i would suggest maybe just putting something behind them such as interior scene or even just a curtain, this gives a more realistic glass effect aswel as showing that the house is not empty....Also brighten the sky up, looks to me that its going to rain, and this is something you dont want to show as it can make any visual look dull unless done correctly...
Hope this helps
Regards