The clouds seem to be too hard. Also, as in many of my renders, the grass color is too uniform. It's something I always forget to fix. Try adding a power fractal in between the image map shader and the default layer with a low saturation brownish yellow color. Use the measure tool to pick a scale size. I usually multiply this by 3 to get a fair lead-in scale.
Breaking up the wall and roof image maps with a slightly off color would help the building. Elongate the color along the y axis for a weathered effect.
This is a nice country scene. I hope you continue to work with it.