I was fortunate enough to be the project manager on a Ricardo Legorreta designed home. One of the most powerful elements Ricardo directed was daylight into the bathrooms. The skylights provided an elevating, sanitizing, and even empowering sense to the space. Paired with the right stone--we used roman travertine--the room glows and rejuvenates you.
Skylights in bathrooms are a must have for me now in any home I have a design say in. It is a modern, clean solution to enlivening this space. The light from above is more natural than light ported in horizontally. Backlighting at mirrors is no longer an issue.
Skylights over the vanity and in the shower are on my checklist. Look at adding them to yours.
I work with someone who told me, "Skylights leak. That's their job.: True enough. You have to weigh this when you build and select the final location of the skylight. There are locations on the roof that are more prone to leaking than others. But to me the tradeoff is well worth it.
And my wife says daylight is so much better when applying makeup. Case closed.