You can use the default of 1.45 for almost everything, unless your scene needs to be 100% accurate to the realworld it doesn’t make much of a difference.
I have re-worked the leaf texture, and in the viewport previews, it does look better. However, that’s not a given that final render will work, so, another 7 hour render overnight to see.
OK, I’ve re-worked external textures again, but I needed to make a start on the interior. And yes, it’s all a single model.
The interior looks good but the lighting makes it hard to tell if theres anything significantly wrong with the materials/objects.
I can see that the ceiling has a noticable tiling pattern to it and that the leather furniture looks alittle bit too shiny and perfect.
And personally I think that rug is pretty ugly.
lol, I know the ceiling is wrong, and the leather is a WIP (but you knew it was leather, which is a bonus). As for the rug, it’s meant to be ugly. Whatever gave you the impression that this was a house for people with taste.