Small-scale passive house
Renovation of old buildings in Wassenberg, North Rhine-Westphalia
Advantages for new construction and renovation
However, the use of a high-performance insulation system does not only make sense in such a special case as the Wassenberg Passive House. The slim system structure also provides extensive advantages for conventional buildings. In new buildings, for example, particularly filigree facade constructions and a gain in living space of up to eight percent are possible. In the case of renovations, the conversion costs for adapting roof overhangs and detailed connections are lower or even completely eliminated.
Double insulation is better
By using the high-performance insulation system, a layer thickness of 240 millimetres was sufficient to achieve the required insulation performance in the Wassenberg building. The insulation boards were laid in two layers of 120 millimetres each. By comparison, a conventional ETIC system with a thermal conductivity value of 0.040 W/mK would have required an insulation layer of 440 millimetres. This would have turned the house into a bulky block.
Only with high-performance insulation material
In Wassenberg, the architect Prof. Ludwig Rongen succeeded in bringing his 74-square-metre cottage down to a heating oil consumption of 1.2 liter. Of course, comprehensive measures were taken in the window areas, the heating and the ventilation to achieve this remarkably low consumption. However, according to the owner and architect, the decisive contribution was made by the facade insulation. The ETICS weber.therm plus ultra was used, which has a record insulation performance of 0.022 W/mK thanks to a new type of insulating material made of Resol (phenolic) rigid foam.
Passive house in small format
Converting an old building into a passive house is nothing unusual nowadays. The conversion only becomes a real challenge when the ground area of the building is smaller than 100 square meters. This is mainly due to the ratio of the facade surface to the space volume, which has a decisive influence on the heating energy demand. Especially in small, detached houses, the surface area is disproportionately large compared to the volume - and so is the heat loss. Therefore, in such buildings, the heating oil requirement of 1.5 liter per square meter prescribed for passive houses can hardly be achieved with conventional facade insulation. Modern high-performance insulation systems offer a solution, as demonstrated by the example of an old building renovation in Wassenberg, North Rhine-Westphalia.