Insulating sheets and films of polymers, foils, paper and laminates comprising combinations of one or more of these materials for insulating and lining buildings; films, sheets and laminates comprising polymers, foils or papers or combinations of these, optionally reinforced with fibres or like materials, used within walls, floors or ceilings of buildings and houses for the purposes of insulation or lining; films and insulating materials for lagging; insulating materials for buildings