This is the image we will use to add the snow effect to.

The image size is 12 inch X 8 inch and the resolution is 100. Adjust the colors of this image.
Go to "Image -> Adjustment -> Hue/Saturation" and reduce the saturation and lightness.

Double click the layer and select blending option "add gradient overlay" for the following values.

Use the pen tool and select the marked area. (see the yellow line)

This image shows you the path.

Right click the path option, and select "make selection".

Enter the feather radius 1 pixels.

Now create a new layer and fill the path selection with white color.

Select brush tool from tool menu and select "spatter 27 pixels" brush from the brush gallery and enable the scattering option. (see the image below)

The brush size is 25.

Use the brush tool and select the white color and brush the edges so they look like the below image.

Apply the same steps on the other side.

And little bit of brush on the walls, windows and trees.

Select the grass and fill it with white color.

Touch the edges with Brush tool.

Then go to "Layer -> New adjustment Layer -> Gradient".

Enter this value.

Now create another new layer and fill it with black color.

Then goto "Filter -> Sketch -> Graphic pen".

Apply these values.

Now set the blending mode to "screen" and reduce the fill to 80%. Then go to "filter -> blur -> motion blur".

Apply the following value.

This is the final image.

Hope you enjoyed this tutorial. Good Luck!