BREAKDOWN - For this Earth Hour video I first shot a picture of the building during day time. In Photoshop I masked out the sky and removed it. In After Effects I then added back a starry night sky. After that I masked out the windows and made everything else from day to night with color grading. Finally I comped in the light beams from the street lights. After the main comp was done I animated the layers making it look like the lights turned off one by one.
The entire project took me about 3 hours to complete including shooting the image, so it was a rather quick task.
The final timelapse video.