Well, it's a start but I would consider it far from done.
I'll try to quickly go over what I see image by image to make things more clear.
[01]
-the grass has no self-shadows and therefore looks completely artificial, more like something painted than realistic
-AO on the roof is much too black, that would never happen in reality
-there are no shadows to speak of except from excessive AO
-if you have no interior modeled, it is usually preferable to do a daylight scene with the glass being slightly reflective to obscure the lack of detail on the inside
-the vegetation looks much too big for the model, I suppose you just scaled it up
-everything on the image is too blurry
[02]
-you can see the excessive AO on the inside walls
-the bricks look weird, like something is wrong with smoothing, or a too strong/too blurry bump.
-the background vegetation seems pasted on, it doesn't seem to sit naturally in the scene
[03]
-you can see the leaves being clipped by the ground plane
-the fence is not really appealing, nobody would put a prison-style fence around new houses like that
-car materials are a bit plastic-looking, and the red tail-lights on the left one look really fake, avoid things like that
[04]
-it is better to put two cars in a scene in a smart way, than to copy the same car over and over
-the chairs on the left-most terrace flew apart
-the ground texture is scaled wrong and looks blurry and fake, especially apparent in the corners
A good place to start would be to bring in some sun or a good HDRI, and get more dynamic lighting with real shadows.
Find some better plant models, there is free stuff all around the web.
Take a look around the forums, there are beautiful images by very talented users here, try to analyze how they achieved the atmosphere in their images.
Some of the artists here have blogs with very useful tutorials, find them and read them.
I know you probably don't have time to do all that on this project, but try to study lighting and materials a bit more.
Unfortunately I have no clue about Blender so I can't help you with specifics, but good luck anyway and keep it up! :)