Many architects are fond of skylights. Admittedly, skylights can effectively bring more natural light into the library. However, some cautionary advice I got a while back at a Public Library Association conference on the good and evil in library architecture was: skylights cause impossible glare, but they make up for it by leaking.
I just came across a manufacture that has created a guaranteed “No-Leak” skylight that takes the fear out of installing skylights. These skylights also provide better energy efficiency, light transmittance and solar heat gain. The manufacture is Velux USA.