Whats the use?

[Rhasputin]

Yes if you turn it on its side it makes you do make a "20 inch wide" area, but with the glass being on top which would make a 12 inch ceiling how would you heat the enclosure?

I already said in my post above.

I have 2 heat lamps on top of my bearded dragon, which are powerful enough to heat the enclosure to the proper temps, including the hot spot. I provide a ramp for the bearded dragon under on of the lamps, which creates a basking area right under one lamp which provides enough heat for a hot spot, and the other end of the tank, has a less powerful lamp, for a cooler side.

The skink is heated with a small heat mad on the underside of the tank, and 1 heat lamp above the tank as well. The glass radiates enough heat to provide them both with good heating. I wish I could reliably cut holes in the glass, because it would be more... 'professional' looking, but I can't do that. Though I was surprised how easily I got proper temp regulation through the glass.

UVA/UVB does not work through glass, so I hang those lights on the front of the cages to provide UVA/UVB rays.

And neither skinks nor bearded dragons need a ceiling that is any higher than that.