I am looking at options for improving insulation in a solid brick external wall. The property is a 1930 semi with solid brick construction. My thoughts are battern wall and fix Kingspan K7 board which has plasterboad, 60mm insulation and vapour barrier all in one. Questions I have are:
1) Can the batterns be fixed to the existing wallpaped walls or should I strip the wall back first to remove the old wallpaper?
2) I have read the batterns shoud be treated but not sure what this means do I buy battern pretreated and if so what are they treated with?
3) Does dry lining need Building Reg approval?
4) To avoid impacting the size of the room too much, on the external wall with the chimney breast I was thinking of only dry lining the two recesses, does this make sense or should I dry line and insulate the chimney breast as well?
5) Is there another option you think I should consider?
6) I am also thinking of plaster boarding the ceiling in the house with 9mm board as existing ceilings are papered or have polystrene tiles. Should I remove the old ceilings lathe and plaster and decorations or is it standard practice to just dry line on top of the existing decoration?