Because they use a dual layer construction with an air gap between the inner an outer walls. This gives space for condensation to occur and evaporate again without effecting the living space.
In old buildings with solid walls you can get condensation on the walls that will evaporate because the living space is heated and we'll ventilated. If you clad that wall in insulation you can prevent the evaporation which leads to damp problems.
In old buildings with solid walls you can get condensation on the walls that will evaporate because the living space is heated and we'll ventilated. If you clad that wall in insulation you can prevent the evaporation which leads to damp problems.