Situated on the vibrant edge of Vienna’s ‘Village im Dritten’ urban development area, the STADTREGAL residential complex – comprising four buildings offering a range of living standards – forms a striking focal point of the new neighbourhood. Developed in collaboration with heri&salli, the housing project embodies social and ecological coexistence. As the first building of this scale in Europe to feature a urine-separation system, it pioneers the implementation of ecological cycles within subsidised housing and makes a significant contribution to the field of wastewater management.

On the one hand, the development responds to the ‘noisy’ yet vibrant urban context, with the adjacent railway line and road; on the other hand, it capitalises on the attractive west-facing orientation and evening sun, made possible by the height of the buildings. Different floor plans are developed depending on the position and orientation of the buildings. Through-apartments and maisonettes in the hybrid timber structures are complemented by two-storey townhouses, each with its own entrance. Alongside attractive, flexible flats and expandable units, the focus is on housing for young people. With 127 flats, small commercial premises and office space, the diverse residential development and tranquil inner courtyard create a varied living environment – with a forward-looking approach to flexible living arrangements. All buildings are connected on almost every floor via green open spaces or roof gardens, fostering interaction amongst the residents.

The importance and necessity of environmental and social approaches to sustainable neighbourhood development are conveyed at various levels: spacious open and communal areas, a youth centre and an eco-playground serve as meeting places both within the housing community and beyond. Furthermore, a neighbourhood cinema and alternative mobility concepts provide an attraction that extends across the development site, benefiting the entire neighbourhood and the wider urban community. We were able to secure Volkshilfe Wien as a social partner for the neighbourhood.

Thanks to its specific focus on social and environmental aspects, it is the first building of this scale in Europe to incorporate a urine-separation system. Separate wastewater disposal is crucial, particularly for rapidly growing cities, in order to prevent long-term pollution and damage to surrounding water bodies. The ‘save!’ urine-separating toilet installed in the building was developed jointly by the Austrian design studio EOOS, LAUFEN, and the Eawag water research institute at ETH Zurich.

The fertiliser obtained here through the processing of separated urine is, in turn, to be used for the maintenance of the building’s own green spaces. In this way, not only are valuable resources such as phosphorus and nitrogen recovered and reused, but the burden on sewage treatment plants is also eased and nutrient overload in the environment is reduced.