Those are some incredable clouds to work with, great job. I might say to cut off some of the waste black space at the bottom, but it seems to add the picture. Very nice work.
OMG...construction has never been so beautiful...what an amazing rich, lush image...love the smoky tones and the stark simplicty of the composition...the light is gorgeous...very nicely done....absolutely one of my favorites in the challenge...the only question I have is was the maximum 640 pixel dimension used...it seems like this could be a bit larger...still a stunning image even at this size.