The Wälderhaus in Hamburg is all about forests and sustainability. To guarantee that its insulation fits into the concept, the flat roof is insulated with materials of Neopor®.
The Wälderhaus is a high-caliber sustainability project on the grounds of the International Building Exhibition (IBA) in Hamburg-Wilhelmsburg. It is sustainable in the way it’s been built, and memories of it will be just as lasting owing to its appearance. The larch facade brings the forest into the city and proves that architecture can be both efficient and attractive.
Multifunctional on all levels
The Wälderhaus is a high-caliber sustainability project on the grounds of the International Building Exhibition (IBA) in Hamburg-Wilhelmsburg. It is sustainable in the way it’s been built, and memories of it will be just as lasting owing to its appearance. The larch facade brings the forest into the city and proves that architecture can be both efficient and attractive. Schutzgemeinschaft Deutscher Wald (SDW), an association devoted to protecting German forests, not only wishes the multifunctional building to outwardly set standards, but has also set sustainability goals for the five-story complex: Primary energy demand is 50% and transmission loss 30% below the levels demanded in the Energy Conservation Ordinance (EnEV) at the time of construction in 2009.
Versatility on flat roofs
To meet these targets, it was essential to use efficient construction materials. For the flat roof, insulating materials of Neopor® were employed – roofs are a special challenge because a lot of energy can be lost if they are inadequately insulated. However, Neopor® demonstrates high standards of energy efficiency, achieving a U-value (heat transfer coefficient) of only 0.111. Instead of the usual value of 0.20, this represents an improvement of almost 50%. Neopor® also enables a variety of flat roof uses: Adopting the Wälderhaus approach, 9,000 bushes and 500 trees have been planted on the greened roofs. The advantage of Neopor® insulating materials is that they absorb very little water in the event of roof damage. In addition, the insulating material is dimensionally stable and virtually immune to aging and degradation. And it permits up to 20% better insulation performance with suitably slimmer panels.
Energy-efficient for novel methods
Neopor® from BASF consists of little black beads of expandable polystyrene (EPS) granulate containing blowing agent. The processing of this material into insulating panels makes it highly versatile, as the Wälderhaus shows. During installation itself, the use of Neopor® paid off, as the task was swiftly accomplished thanks to its low weight. Owing to the material’s composition, the panels were cut to size virtually dust-free. Thanks to the ease with which it can be cut to size, sloping roofs can be produced at little cost. Sloping roof systems make a great deal of sense, as they ensure that rainwater drains off the roof. Roofs without a fall on which water can stand for a long time are exposed to extreme stressing, and this can be expected to shorten the roof’s life. So that accumulating water can drain off well, flat roofs should have a minimum fall of 2%. Thanks to tapered insulating panels of Neopor®, a fall was created on the roof of the Wälderhaus without a prior sloping screed. For the building at Wilhelmsburger Inselpark, which accommodates not only a Science Center dedicated to Forests and Sustainability, but also a hotel and restaurant, efficient thermal insulation has been achieved – without encountering esthetic limitations. Hamburg’s cityscape has thus gained a new sight that is both attractive and sustainable.