When I tried solving this puzzle, I kept coming up with rectangular lights where the sides didn't equal each other. There wasn’t any way to stack eight squares so that they form a larger square. So I devised a questionable solution that divides the window into eight lights (glass sections) and one solid section. This is not really what the puzzle asks.

Think much more creatively. Read the problem very carefully. Notice that the puzzle never uses the word 'square'.