I really like the use of shading. I think you could easily put a little more subtle shades of stucco-white and make it not quite stucco white on the left of the windows and doors. Just a little, as stucco itself isn't smooth, and there'd be uneven bits that would cast small shadows on the wall to the left of each window. I think that I wouldn't even make this suggestion if you didn't already have a really good handle on the shading..... my eye was following the lines, and my thought was, "Nice shading, nice shading, ooh, I like that, but what is off? What gives it a little flatness.... ahah! the windows and door would have shading! Just a thought.
