Hey badmonur, I have a few words of critic since I'm into arch-viz too
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
The first two renders have too big field of view. Narrow interiors, like bathrooms, are actually the only cases you should use FOV that big.
The twin skycrapper is nice, but it's missing st least basic interior (or at the very least floor condignations).
Fourth render: perspective of the background mismatches the perspective af the render. Also, It's night on the outside, yet pretty strong light comes through the windows.
The bridge is very nice. I like it's futuristic design. Even the lack of materials/textures is acceptable, as designs like this are often presented that way. Water is the only glitch here.. I don't know if it's bump map is some crazy squareish noise, or a low quality jpg... it looks weird :]
The bathroom design is pretty good. But, though the interior feels warm an nice, that intense yellow light would be pretty tiring for the eyes.
Next villa is pretty good. I'd only suggest you try to recreate more natural lighting. Right now it looks like lit by some environment light an a few omni-directional lights. Try to light exterior scenes only with environment and one directional light simulating the sun. I'm pretty positive there's a special light for this in you Advanced Renderer. You might also look for a camera correction tool to aquire two points perspective (all the vertical lines are parallel).
One last tip - give some more attention to the shaders/materials. Rendered objects gain a lot thanks to realistic materials.
Keep it up, you're doing good making this stuff in a week
![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)