Ok, um…
Ambient worked, pump it up to 13.
Now what you probs want to do now is… either add some cool light on the building, then add light entity or whatever 
Or you can just make a light entity with like 1000 value, put it in the middle or something, then run it and see.
ORRR (The best I think), is where you have the windows that look like they are lighted, but light entities around that with value of 200+/500-. That would look nice. You could maybe add some more windows by the corner with the light entities 
Try it out and post again plzzz.
- MaTT