The wall is an outside wall and is rendered externally with the chimney flu ventilated from above The old stone wall itself is strapped and finished with lathe and plaster and the fireplace has been framed and boarded over. The brick fire surround has been plaster skimmed and feathered onto the old finish. During the winter months especially the cold from the brick surface together with overnight breathing leaves condensation on that part of the wall. Initially I was going to go the stud partition route but the mess has got me interested in suitable alternatives which (mess) presumably would have to involve leaving the existing coverings in place? I'm also mindful of the possibility of displacing condensation to elsewhere. Would be interested in some ideas I may not have even thought about together with the make up of any changes?