When you convert a loft in an old terraced house, the brick walls in the loft area (party walls) are normally made from solid 9 inch brickwork. So if I run the new stairs up the party wall, the wall below the ceiling is adjoining another ‘warm’ wall. But when it passes through to the loft area it will be adjoining a ‘cold’ wall. Is this normally ignored by the Building Inspector, or do I have to have a nasty looking step in the wall, with some form of insulation behind?
Try polyurethane foam for insulation.I have tried ultimate linings polyurethane foam.It’s materials offer high R values, one can use a thinner foam board to have the required thermal resistance one desires. This can be extremely helpful if there are space limitations involved. This strength involved the ability of the foam to resist deformation and the ability to main its shape when forced or loaded down.