Since the room is glass is should work, but i dont have the mats yet to make glass to try it myself.
I wish HG would have made it possible to place them on top of buildings, but you can only place them on the center square area and there’s only room for a few.
Then I figured to try 4 Cuboid Rooms in a square, so just a single floor, no light from outside. This unexpectedly actually works fine as well!
Will add some screenshots of the Cuboid rooms in a sec.
I’m not surprised. They either thought of checking the indoors flag, or they didn’t. The game being able to differentiate between indoors with or without sunlight would really have surprised me.