We pretty much do everything he says, so when we were looking for a way to get some natural light in the master bathroom and he suggested a roof window, I said yes without even knowing what one is.
A roof window is an awesome invention and is NOT a skylight. It's an actual opening window on the roof. It cranks open at a 45 degree angle and lets in fresh air and tons of natural light to the bathroom. Ours is the Velux brand and looks a little like this one only smaller.