Well, that makes sense, really. If you look at the sleek door, there is a big glassless window right there is the door. You can see right through to the outside. He is going to need a mod called let's say.......... windowless sleek door, or glass windows in doors. Or something to that effect.  🤣😇

Hey StraiteCash

I went and tested it, it looks like the sleek door doesnt insulate the room.

I built a dirt room in creative and put raw redmeat in a clay storage vessel.

just the meat in the vessel lasts 6 days.

I found that when covered by just dirt (I was using packed arid dirt in my testing) it lasts the longest, 19 days. 

If I added a solid door, it dropped to 18 days. 

if I open that solid door, it dropps to 16 days.

If I replace that solid door with a sleek door it drops all the way back to 6 days.

So to answer your question, yes you will need another mod to make it insulating if that is what you want.

My understanding is that in 1.20.3 of VS that all doors act as insulating for rooms. I haven't tested that specifically though.

I really appreciate the ability to create Sleek doors, so I appreciate you greatly for taking the time to create this mod. Even with the tutorial on the wiki I find myself far too busy with other work to try and learn that stuff. Ironically I'm out here making real doors and other pieces of furnature. But enough about myself, I wanted to ask if the doors are considered insulating for room construction, or will I have to download another mod for that?