hidden air leakage paths

Many buildings in Sweden are in need of renovation in order to meet the current standards of energy use in buildings. Particularly challenging are old listed buildings, the majority built before 1950, because the renovation is restricted to the parts that do not change the appearance of the building. This paper presents experiences gained during the renovation of a listed building where aging of materials, movements and settlements during the building operation have left trails in form of air leakage paths that are difficult to cover by renovation.