Description

The four residential buildings with 185 apartments not far from the government quarter in St Pölten in Lower Austria look like ships that have dropped anchor. The maritime metaphor is unmistakable even from a distance: the four, slender, nearly 80-metre-long structures with their set-back decks; the yellow, white and black speckled facades of the first two buildings; and finally, the access footbridges running around the structures.

What makes this housing innovative is that its primary structure is essentially that of a cheap car park construction system within which spatial constellations have been developed that one doesn’t see in most conventional housing. The basic module is a parking garage unit with its generous spans. Instead of the modular stacking of boxes, the project employs the stacking of reinforced concrete floor slabs. The project is building on the Peikko system, which was developed in Finland but was in this case produced in Hungary. This garage type has a “Deltabeam” that is the same depth as the floor slab and can be used with most slab systems to achieve wide spans with moderate ceiling thicknesses. As a highly economical means of construction, it is predestined for multi-storey residential building, especially when, as here, the gallery access principle is used to afford maximum freedom from columns in the floor plan.

An interesting aspect is the consequences this has for the design: the system both limits and extends architectural freedom in equal measure. On the one hand, it is restricting because the facade design becomes essentially a question of designing the infill sections in the structure. Fire protection requirements dictate that the cantilevered leading horizontal edge plays a defining role. Inside, however, design freedom is greater as the regular columns are the only fixed points. Walls can be installed or removed where they are needed. As the ceilings span the entire width of a unit, spaces can in principle be left open at no great cost, inviting architectural experimentation or making it possible to create communal spaces. Such programmatic freedom is comparatively rare in housing construction. A second characteristic is the bulky outer form resulting from the stacked platforms. The buildings’ presence needs a corresponding urban arrangement, hence the sculptural impression of four ships moored along a quay. This arrangement automatically creates spacious courtyards, also comparatively rare in housing construction today.

The perhaps most characteristic element of these four buildings, however, are the access walkways and balconies around the perimeter, which at 2.80 metres are unusually wide. On one long side, they serve as pergolas, on the other as deep balcony areas. These room zones in front of the building invite the residents to extend their living space out into the open on both sides and put it to their own use. The intention is that over time they will be transformed into green zones similar to Stefano Boeri’s popular “Bosco Verticale”.

The four buildings in St Pölten are the successful first prototype of this system, and further applications and test scenarios are in planning. In typical cross-wall structures with multi-layer insulation, one does not find such high-quality insulated timber facades. In typical housing projects, semi-public spaces are often provided only in homeopathic doses whereas here they are generous and spacious – a side-effect of the construction method. As such, there are good reasons why parking garage systems could be a viable basis for multi-storey housing construction, and the time has come to investigate and expand their application in further scenarios.

Originally published in Bauwelt 21.2018, pp. 22-29, abridged and edited for Building Types online, translated by Julian Reisenberger

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