Hi All looking to insulate/board out inside of summerhouse. my thoughts are tanalised 2x1 screwed to the blocks, then fix the insulated plasterboard straight onto the batons, most likely the below product. https://www.buildingmaterials.co.uk/knauf-thermal-laminate-tapered-edge-plasterboard.html once fixed then tape and join and paint direct onto the plasterboard. the room will be heated with 2no electric wall heaters and a stove for when its really cold. do you think this will be sufficient and can you please advise on whether vapour barrier would be wise to avoid any damp ingress/mould? Thanks George