Im hoping someone can help. I have a 1907 granite stone house. I have removed all of the old lath and plaster and am looking to insulate everything. For my external walls I was considering framing the walls with 3x2 posts, then insulating with 75mm of kingspan and plaster boarding ontop. I have just been looking at insulated plasterboard and reading about thermal bridging. Would I be better to make my frame of 2x2 posts with 50mm kingspan and 25mm insulated plasterboard ontop?
Any advice is much appreciated.
John