Housing, Vienna

Urban development areas often have something bleak about them. That also goes for Tokiostrasse in Vienna's Donaustadt. Blocks of flats stand to the right and left of the wide street and more and more are being added all around, but there is hardly any infrastructure. It is early March and an icy wind sweeps through the streets. Just as everyone waits longingly for spring this year, so this street is waiting to become city – and will probably have to do so for years to come. One of the last vacant lots in Tokiostrasse has now been filled by ARTEC Architekten with a seven-storey block of flats.

One would think that such a multi-storey residential building would be easy to describe, especially since architects, particularly in Vienna, are always complaining about the lack of design leeway. But Bettina Götz and Richard Manahl of ARTEC Architekten did not take the easy route. The building at Tokiostrasse 6, delivered in mid-February, is like a children's surprise Easter egg: dark on the outside, yellow and full of surprises inside. As many as five different housing typologies, more usual on the edge of town than in an urban neighbourhood, were stacked next to and on top of one other by the architects. The building's 100 flats are divided among two parallel wings and one transverse link.

On the ground level are studio flats consisting of a large sitting room, an open loft space and a terrace. Above them are dwellings facing an inner courtyard and, above that, classic terraced houses. Both the latter types are two storeys high and have their own outdoor space. Perched like a crown on top of the building is a series of miniature two-storey houses. They are 5.5 metres wide, narrowing to a mere three metres on the courtyard side, a trick that enabled the architects to bring sunshine into the inner court much earlier in the day as well as right down to the lowest flats. These top-level residents have their own inner court from which they access their mini-homes. Even though each dwelling in this building is one of a hundred, it offers its occupants maximum privacy: concrete panels block the view of the neighbour's terrace, there is a comfortable distance between facing dwellings and the terraces all have a strip of greenery along the railing as an additional privacy buffer.

The three two-storey housing types are all oriented towards the internal courtyard. Facing the street, on the other hand, are single-storey flats. Manahl calls them 'Casablanca flats' as their ground plan was developed by Jean Hentsch and André Studer for Habitat Marocain in Casablanca. In front of the single-storey flats is a double-height outdoor space, which means that no upstairs balcony can deprive their living rooms of sun. The loggias are like triangles cut into the flats and likewise guarantee plenty of privacy.

The building by ARTEC Architekten projects such a feeling of spaciousness that it is hard to appreciate just how dense this development is. Moreover, it is so complex that it even puts professionals to the test, let alone the average housing consumer. Whatever the case, it proved impossible to market the dwellings using classic sales portfolios. The developer finally resorted to the architectural model to explain the building and the ground plans in more detail to interested parties.

The occupants are only gradually taking possession of the building. Here and there, colourful doormats have already appeared in front of their doors. But it will not take long for the spacious entrance hall and the semi-private areas in front of each private entrance to be taken over. 'It was meant to be a robust building,' says Manahl, 'which can withstand a lot. Concrete therefore plays a major part'. On the outside, the reinforced concrete structure is painted off-road grey. The stairwells are bright red and interior hallways are yellow. They create a cheerful feeling, as if the sun were shining all the time.

Bettina Götz and Richard Manahl have been designing housing for a long time. In her capacity as curator of the Austrian pavilion at the 2008 Venice Architecture Biennale, Götz even made housing the main theme. This is a firm that wants to make something happen. This block of apartments, which evolved out of a developers' competition and was realized in collaboration with Neues Leben, a developer considered innovative, was therefore a good opportunity to push the envelope and show that things can be done differently for a change.