Residential complex in Dornbirn
Of particular importance to the residents of the Wieden 90-98 housing complex in Dornbirn (Austria) was the visual enhancement of their neighbourhood. VOGEWOSI, the state’s largest non-profit housing association, however, sought to achieve more: the association aimed to refurbish the buildings to “factor 10” renovation standards. By applying these standards, heating requirements would be reduced from 250 kWh/m²a to about 25 kWh/m²a. In the end, even more was achieved: the Vorarlberger Energy Certificate indicates that after renovation the buildings require a mere 14 kWh/m²a for heating purposes. This low level was achieved through numerous measures, typical for passive building design. The basement ceilings were insulated from beneath, while the ceilings in the upper floors were insulated from above. The exterior walls, previously double brick construction with a 3 cm core insulation, were fitted with 25 cm of new composite thermal insulation. New, triple glazed windows replaced the old double glazed units. In contrast to their predecessors, the new windows were set into the insulation layer, so that from the outside their massive appearance would be reduced. All buildings were fitted with mechanical ventilation with 80 % heat recovery. The ventilation facilities were constructed as a “room within a room” in the previously unused attic space. From there, the ventilation ductwork passes down through the stairwells, behind the suspended ceilings in the apartment hallways, and further into the individual rooms. While the roof structure remains in its original condition, it has disposed of its massive prefabricated concrete gutters, and a new covering of light grey fibre-cement shingles has been added. The heating facility, too, is only partially new. The radiators in the apartments were maintained, but are now fuelled by a gas condensation boiler.
