Hi there, not much to add beyond the question in the thread title other than context currently building out the stud framework for a new understairs WC (toilet and basin only). Tight for space on the width and trying to claw back every cm I can. We are planning tongue and groove panelling all the way around about a metre high and then the top half of the room a paintable skimcoat. question is if the wood panelling NEEDS plasterboard underneath it or can it be placed directly onto the studwork & battons underneath? Is there any advantage to having plasterboard under panelling?