Ooo, baby! This is a wonderful job. The bile of covetousness rises in my throat.
You are correct in your preamble that clients focus on incongruity. By eliminating color you bring the sense of grassland villa to the forefront.
The project has the advantage of a bucholic site and site photography to captivate the eye. Try doing this in a city with fire hydrants and overhead wires. Where is this?
If i was to criticize, it would be that in Archicad, Lightworks needs work to keep murkiness out of the shadows. Stylizing the image like you've done minimizes this liability.
Dwight Atkinson