Help with this problem

This is really annoying, there is any way to remove those things? (not union, it removes the studs texture

Why are you unable to extend one of the walls the full way?

I am making a hole in a wall, thats why

Aren’t unions a BasePart? After you union them they should still have the Surface properties

No, i can’t put the studs texture on a union

Unfortunately, that’s how the engine works transparency wise - there’s no way around it if you can’t union it, turn the transparency low or extend it the whole way.