I used to have a "screen" window, it set just above panel level. The window edges fit together so it looked like one strip of wood between the "screen" (which DID look like screen if you got close enough). Sadly, someone actually made this for me; don't know what happened to it. Anything that will look like a screened in patio, and will act like a window (not like a non-enclosed room). My grandmother had a room called a "summer bedroom" upstairs, it was where you could sleep when it was really hot, that had screens all around it.

Rebeccah at Affinity did a screen wall and door. Not sure if it's here on MTS too, but I know it's over there. I have it, but haven't used it in game yet.... much like a lot of stuff I got ... lol

Here ya go Wall and Screen Door

Another by Rebecah here too, looks like a different one http://modthesims.info/d/243958
Shakeshaft has a set too https://www.thesimsresource.com/dow...ims2/id/875435/

Thanks. Both of these look like they are made from the greenhouse; can't remember if that will be considered "inside" by someone sleeping there, but will test. Shakeshaft has a screen door, but the "screen window" just looks like a window.

I don't know about sims and sleeping, but lights won't consider it "inside." There won't be any option to "turn on/off all lights...this room."
Edit: To clarify, I'm talking about the greenhouse walls; I've never tried any of these CC screen walls.

I use Rebeccah's screen walls and doors and never had a problem using lights. But of course when I build the home I use real walls frist and put a real roof over it, then knock out the walls and replace them with the screened ones.