Proton 42.5 unfilled or 36.6 filled?

Thank you for the feedback.

From what I can read here, we will not do anything wrong with the 36cm filled brick and KS interior walls. I did some research yesterday and see that the brick manufacturer offers filling with mineral wool and with wood wool (U-value for both 0.18). Are there significant differences?

So wood wool sounds strange regarding moisture .... If you morally don't care about disposing of your bricks, take the MW, otherwise there's still perlite ....